A pH-regulated fluorescence covalent organic framework for quantitative water content detection in methanol

In this paper, we designed and synthesized a two-dimensional fluorescent covalent organic framework (TAPB-DMTP-COF) for the precise determination of H2O content in methanol. The COF was synthesized using two typical monomers by grinding method, which significantly reduced the synthesis time. By adjusting the pH value of the COF suspension to 4.0, the portion of the COF material structure is disrupted, thereby mitigating π-π stacking and resolving the aggregation-caused quenching (ACQ) effect. Consequently, the non-fluorescent TAPB-DMTP-COF exhibited blue-purple fluorescence emission in methanol. At the same time, it is observed that in the presence of H2O, there is a red shift in the maximum fluorescence emission peak of TAPB-DMTP-COF, which correlates with the H2O content within a specific range. Notably, this redshift demonstrates a linear relationship with H2O content from 4% to 80% in methanol. Our work presents novel insights for efficient analysis and detection of H2O content in methanol and could be used for H2O detection in other organic solvents.

[A randomized controlled trial on the effect of early eschar dermabrasion combined with antimicrobial soft silicone foam dressing in the treatment of deep partial-thickness burn wounds in children]

Objective: To explore the effect of early eschar dermabrasion combined with antimicrobial soft silicone foam dressing (hereinafter referred to as foam dressing) in treating the deep partial-thickness burn wounds in children. Methods: This study was a randomized controlled trial. From June 2021 to December 2022, 78 pediatric patients with deep partial-thickness burns who met the inclusion criteria were admitted to the Department of Burns in Guiyang Steel Plant Employees Hospital. According to the random number table, the pediatric patients were divided into two groups, with 38 cases left in combined treatment group (with 20 males and 18 females, aged 26.00 (16.75, 39.75) months) and 39 cases in foam dressing group (with 21 males and 18 females, aged 19.00 (14.00, 31.00) months) after the exclusion of one dropped-out child in follow-up. The pediatric patients in combined treatment group underwent eschar dermabrasion of the wound within 48 hours after injury, the wound was covered with foam dressing after operation, and the dressing was replaced once every 7 days; for the pediatric patients in foam dressing group, the wound was sterilized within 48 hours after injury and covered with foam dressing, and the dressing was replaced once every 2 to 3 days. After the wound healing, the children in both groups were routinely applied with silicone gel twice a day for 3 weeks before started wearing elastic sleeves for more than 18 hours a day, and continuously for over than 6 months. The degree of pain during dressing change was evaluated using the children's pain behavior inventory FLACC. The adverse reactions during the treatment period, number of dressing changes, and wound healing time were observed and recorded. Six months after wound healing, the Vancouver scar scale (VSS) was used to evaluate the condition of the wound scar. Results: When changing dressing, the FLACC score for pain of pediatric patients in combined treatment group was 3.5 (2.0, 5.0), which was significantly lower than 6.0 (5.0, 8.0) in foam dressing group (Z=-5.40, P<0.05). During the treatment period, no adverse reactions such as wound edema, fluid accumulation, or peripheral skin rash allergies occurred in any pediatric patient in both groups. The number of dressing changes of pediatric patients in combined treatment group was 3 (3, 4) times, which was significantly less than 8 (7, 10) times in foam dressing group (Z=-7.58, P<0.05). The wound healing time of pediatric patients in combined treatment group was (19±5) days, which was significantly shorter than (25±6) days in foam dressing group (t=-4.48, P<0.05). Six months after wound healing, the VSS score for scar of pediatric patients in combined treatment group was 5 (2, 8), which was significantly lower than 7 (5, 10) in foam dressing group (Z=-3.05, P<0.05). Conclusions: Compared with using foam dressings alone, early eschar dermabrasion combined with foam dressings can reduce the number of dressing changes, alleviate the pain during dressing changes, and shorten the wound healing time in treating children with deep partial-thickness burns, and effectively alleviate scar hyperplasia by combining with anti-scar treatment post burns.

Selective detection of ascorbic acid by tuning the composition and fluorescence of the cesium lead halide perovskite nanocrystals

Lead halide perovskite nanocrystals (PNCs) have attracted intense attention due to their excellent optoelectronic properties. In this work, a series of water-stable CsPb(Br/I)3PNCs fluorescent probes were prepared using an anion exchange method. It was found that the PNCs probes could be used to detect ascorbic acid (AA) in water, and interestingly, the FL spectra of the PNCs probes can be adjusted by controlling the concentration of KI in anion exchange to improve the detection selectivity of AA. The high sensitivity and selectivity make CsPb(Br/I)3PNCs an ideal material for AA sensing. The concentration of AA can be linearly measured in the range from 0.01 to 50μM, with a detection limit of 4.2 nM. The reason for the enhanced FL of CsPb(Br/I)3PNCs was studied, and it is considered that AA causes the aggregation of CsPb(Br/I)3PNCs. This strategy of improving the selectivity of the probe to the substrate by adjusting the spectrum will significantly expand the application of PNCs in the field of analysis and detection.

Chiral Assembly of Perovskite Nanocrystals: Sensitive Discrimination of Amino Acid Enantiomers

Chirality is a widespread phenomenon in nature and in living organisms and plays an important role in living systems. The sensitive discrimination of chiral molecular enantiomers remains a challenge in the fields of chemistry and biology. Establishing a simple, fast, and efficient strategy to discriminate the spatial configuration of chiral molecular enantiomers is of great significance. Chiral perovskite nanocrystals (PNCs) have attracted much attention because of their excellent optical activity. However, it is a challenge to prepare perovskites with both chiral and fluorescence properties for chiral sensing. In this work, we synthesized two chiral fluorescent perovskite nanocrystal assembly (PNA) enantiomers by using l- or d-phenylalanine (Phe) as chiral ligands. PNA exhibited good fluorescence recognition for l- and d-proline (Pro). Homochiral interaction led to fluorescence enhancement, while heterochiral interaction led to fluorescence quenching, and there is a good linear relationship between the fluorescence changing rate and l- or d-Pro concentration. Mechanism studies show that homochiral interaction-induced fluorescence enhancement is attributed to the disassembly of chiral PNA, while no disassembly of chiral PNA was found in heterochiral interaction-induced fluorescence quenching, which is attributed to the substitution of Phe on the surface of chiral PNA by heterochiral Pro. This work suggests that chiral perovskite can be used for chiral fluorescence sensing; it will inspire the development of chiral nanomaterials and chiral optical sensors.

An all-inorganic lead-free metal halide double perovskite for the highly selective detection of norfloxacin in aqueous solution

Lead-based perovskites are highly susceptible to environmental influences, and their application in analytical chemistry, especially in aqueous solution, has been reported rarely. All-inorganic lead-free metal halide perovskites have been considered as a substitute for lead-based perovskites. Herein, a Cs2RbTbCl6 perovskite microcrystal (PMCs), which emits strong yellow-green fluorescence with a maximum emission wavelength at 547 nm, was for the first time  synthesized and characterized. The Cs2RbTbCl6 PMCs could be well dispersed in N,N-dimethylacetamide (DMF), and its fluorescence could be significantly enhanced by the addition of norfloxacin (NOR) in the aqueous solution. We found that the Cs2RbTbCl6 PMCs can be used as fluorescent probes (excitation, 365 nm; emission, 547 nm) to selectively detect NOR in a concentration range from 10.0 to 200.0 μM with the limit of detection (LOD) being 0.04 μM. The Cs2RbTbCl6 PMCs could also be adsorbed on filter paper to fabricate as a fluorescent test paper for visual detection of NOR under 365-nm ultraviolet (UV) lamp irradiation. The proposed method has the potential to establish a new analytical method to visualize the detection of NOR in aqueous environments and also promotes the application of all-inorganic lead-free perovskites for analytical detection in aqueous environments.

Synthesis of a water-stable fluorescence CsPbBr3 perovskite by dual-supersaturated recrystallization method and tuning the fluorescence spectrum for selective detection of folic acid

As an excellent fluorescent material, cesium lead halide perovskite nanocrystals (PNCs) is rarely used for analytical purposes because the PNCs are unstable in polar solvents, especially water. Developing a new synthesis method to prepare water-stable PNCs makes it promising for the detection of analytes in aqueous solutions. Herein, by using the solubility difference of the precursors in different solvents, we successfully synthesized water-stable CsPbBr3 PNCs by a dual-supersaturated recrystallization method at room temperature. We also found that the fluorescence of the as-prepared CsPbBr3 PNCs could be quenched by some small organic molecules, such as folic acid (FA) and dopamine (DA). By using a chloride-induced anion exchange reaction method, the fluorescence emission peak of the CsPbBr3 PNCs could be tuned from 518 to 418 nm and the emission color changed from green to blue. The blue emission chloride-exchanged PNCs have a good selectivity for only FA and a good linear relationship is established between the fluorescence quenching rate of the PNCs and concentration of FA from 10.0 to 140.0 μM, with a limit of detection (LOD) of 0.9 μM. This work expanded the applications of PNCs in the field of analytical chemistry and also proposed a new strategy for improving selectivity by tuning the emission spectrum of a fluorescent probe.

Synthesis of a water-stable CsPbBr3 perovskite for selective detection of mercury ion in water

By using the method of low-temperature crystallization, CsPbBr3 perovskite nanocrystals (PNCs) coated with trifluoroacetyl lysine (Tfa-Lys) and oleamine (Olam) were synthesized in aqueous solution. The structure of the CsPbBr3 PNCs was characterized by many methods, such as ultraviolet (UV)-visible absorption spectrophotometer, fluorescence spectrophotometer, transmission electron microscopy (TEM), and X-ray diffraction (XRD) pattern. The fluorescence emission of the CsPbBr3 PNCs is stable in water for about 1 day at room temperature. It was also found that the fluorescence of the PNCs could be obviously and selectively quenched after the addition of mercury ion (Hg2+ ), allowing a visual detection of Hg2+ by the naked eye under UV light illumination. The fluorescence quenching rate (I0 /I) has a good linear relationship with the addition of Hg2+ in the concentration range 0.075 to 1.5 mg/L, with a correlation coefficient (R2 ) of 0.997, and limit of detection of 0.046 mg/L. The fluorescence quenching mechanism of the PNCs was determined by the fluorescence lifetime and X-ray photoelectron spectroscopy (XPS) of the PNCs. Overall, the synthesis method for CsPbBr3 PNCs is simple and rapid, and the as-prepared PNCs are stable in water that could be conveniently used for selective detection of Hg2+ in the water environment.

[Investigation and analysis of prevalence of musculoskeletal diseases among interventional surgeons in some top three hospitals in Tianjin]

Objective: To analyze the prevalence and risk factors of musculoskeletal diseases among interventional surgeons in top three hospitals, and to provide suggestions for prevention of musculoskeletal diseases. Methods: In June 2022, a self-designed questionnaire was used to collect general information of doctors engaged in interventional surgery (121) and non-interventional surgery (124) in some top three hospitals in Tianjin. The standard version of the Nordic Musculoskeletal Questionnaire was used to investigate information related to musculoskeletal diseases. The prevalence and risk factors of musculoskeletal diseases among interventional and non-interventional surgeons were analyzed. Results: The prevalence of musculoskeletal diseases among interventional surgeons and non-interventional surgeons was 59.50% (72/121) and 62.90% (78/124) . Compared with non-interventional surgeons, interventional surgeons had a higher prevalence of musculoskeletal diseases in the shoulders and upper back, and a lower prevalence of musculoskeletal diseases in the waist. The differences were statistically significant (P<0.05) . Multivariate logistic regression analysis showed that age, weekly time of physical exercise, time of intervention operation, and wearing protective clothing were independent risk factors for musculoskeletal diseases (P<0.05) . Conclusion: The prevalence rate of musculoskeletal diseases among doctors engaged in interventional surgery is relatively high in some top three hospitals in Tianjin, and proper enhancement of physical exercise and shortening of interventional time are conducive to reducing musculoskeletal diseases.

[Clinical characteristics and prognosis of patients with therapy-related myelodysplastic syndrome and acute myeloid leukemia arising from malignant tumors]

Objective: To investigate the clinical characteristics, cytogenetics, molecular biology, treatment, and prognosis of patients with therapy-related myelodysplastic syndrome and acute myeloid leukemia (t-MDS/AML) secondary to malignancies. Methods: The clinical data of 86 patients with t-MDS/AML in West China Hospital of Sichuan University between January 2010 and April 2023 were retrospectively analyzed. The clinical characteristics, primary tumor types, and tumor-related therapies were analyzed. Results: The study enrolled a total of 86 patients with t-MDS/AML, including 67 patients with t-AML, including 1 patient with M(0), 6 with M(1), 27 with M(2), 9 with M(3), 12 with M(4), 10 with M(5), 1 with M(6), and 1 with M(7). Sixty-two patients could be genetically stratified, with a median overall survival (OS) of 36 (95% CI 22-52) months for 20 (29.9%) patients in the low-risk group and 6 (95% CI 3-9) months for 10 (14.9%) in the intermediate-risk group. The median OS time was 8 (95% CI 1-15) months in 32 (47.8%) patients in the high-risk group. For patients with non-acute promyelocytic leukemia (APL) and AML, the median OS of the low-risk group was 27 (95% CI 18-36) months, which was significantly longer than that of the non-low-risk group (χ(2)=5.534, P=0.019). All 9 APL cases were treated according to the initial treatment, and the median OS was not reached, and the 1-, 2-, and 3-year OS rates were 100.0%, (75.0±6.2) %, and (75.0±6.2) % respectively. Of the 58 patients with non-APL t-AML (89.7%), 52 received chemotherapy, and 16 achieved complete remission (30.8%) after the first induction chemotherapy. The 1-, 2-, and 3-year OS rates of the non-APL t-AML group were (42.0 ± 6.6) %, (22.9±5.7) %, and (13.4±4.7) %, respectively. The median OS of patients who achieved remission was 24 (95% CI 18-30) months, and the median OS of those who did not achieve remission was 6 (95% CI 3-9) months (χ(2)=10.170, P=0.001). Bone marrow CR was achieved in 7 (53.8%) of 13 patients treated with vineclar-containing chemotherapy, with a median OS of 12 (95% CI 9-15) months, which was not significantly different from that of vineclar-containing chemotherapy (χ(2)=0.600, P=0.437). In 19 patients with t-MDS, the 1-, 2-, and 3-year OS rates were (46.8±11.6) %, (17.5±9.1) %, and (11.7±9.1) % with a median OS of 12 (95% CI 7-17) months, which was not significantly different from that in t-AML (χ(2)=0.232, P=0.630) . Conclusions: Breast cancer, bowel cancer, and other primary tumors are common in patients with t-MDS/AML, which have a higher risk of adverse genetics. Patients with APL had a high induction remission rate and a good long-term prognosis, whereas patients without APL had a low remission rate and a poor long-term prognosis.

[Correlation of serum lipids levels of Alzheimer's disease patients with sex, age and apolipoprotein E gene polymorphism]

Objective: To explore the correlation of serum lipids levels of Alzheimer's disease (AD) patients with sex, age and apolipoprotein E (Apo E) gene polymorphism. Methods: The retrospective study method was used, and 407 AD patients (142 males and 265 females, aged 52-91 years) were selected from Beijing Tiantan Hospital from January 2015 to August 2021 as the research target, and 894 healthy persons (339 males and 555 females, aged 52-94 years) who did body examination were selected as the control group. The AD patients were divided into four age groups according to the age interval of 10 years, including 85 aged 50-59 years, 163 aged 60-69 years, 119 aged 70-79 years, and 40 aged more than 80 years. The serum lipids levels were detected by biochemical analyzer, including triglycerides (TG), cholesterol (CHO), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), apolipoproteinA1(Apo A1) and apolipoprotein B (Apo B). ApoE gene polymorphism were detected by PCR fluorescent probe method. Mann-Whitney U test and Kruskal-Wallis H test were used to compare the serum lipids levels in each group. Results: The levels of serum CHO and LDL-C were 3.30(1.41,4.82) mmol/L and 1.76(1.39,2.78) mmol/L in AD patients, and 4.84(4.24, 5.56) mmol/L and 2.91(2.36, 3.57) mmol/L in control group, and the levels of serum CHO and LDL-C of AD patients were significantly lower than control group (Z=-15.172,Z=-14.583, P<0.001, P<0.001). The levels of serum HDL-C and Apo B were 1.84(1.30, 3.88) mmol/L and 1.17(0.85, 1.57) g/L in AD patients, and 1.39(1.18, 1.64) mmol/L and 0.93(0.81, 1.09) g/L in control group, and the levels of serum HDL-C and Apo-B of AD patients were significantly higher than control group (Z=-12.249, Z=-9.706, P<0.001, P<0.001). There was no significant difference in TG and Apo A1 between 2 groups (Z=-1.577, Z=-0.408, P=0.115, P=0.683). The levels of TG, CHO, LDL-C in female AD patients were significantly higher than male patients (Z=-2.737, Z=-3.963, Z=-4.417, P=0.006, P<0.001, P<0.001). There were significant differences in TG, CHO, HDL-C, LDL-C, Apo A1 and Apo B among AD patients of all age groups (Z=11.263, Z=10.060, Z=40.246, Z=10.451, Z=24.315, Z=19.922, P=0.010, P=0.018, P<0.001, P=0.015, P<0.001, P<0.001). The serum CHO and LDL-C levels were positively correlated with age (r_s=0.160, r_s=0.174, P=0.001, P<0.001), and HDL-C, Apo A1 and Apo B levels were negatively correlated with age (r_s=-0.312, r_s=-0.272, r_s=-0.146, P<0.001, P<0.001, P=0.003), and there was no correlation between TG level and age in AD patients (r_s=0.086, P=0.082). There were 3 cases (3.33%) of E2, 43 cases of E3 (47.78%) and 44 cases of E4 (48.89%) in AD patients, and 22 cases (12.72%) of E2, 117 cases of E3 (67.63%) and 34 cases of E4 (19.65%) in control group. There was significant difference in Apo E genotype distribution between AD patients and control group (χ²=26.381, P<0.001). Apo E4 was the most common genotype in AD patients, and the proportion was 48.89%. Except for Apo A1(Z=7.821, P=0.020), there was no significant difference in TG, CHO, HDL-C, LDL-C and Apo B levels among all patients with different genotypes (Z=3.732, Z=1.677, Z=1.455, Z=1.619, Z=2.202, P=0.155, P=0.432, P=0.483, P=0.445, P=0.333). Conclusion: The levels of CHO and LDL-C decreased while the levels of HDL-C and Apo B increased in AD patients. The dyslipidemia in AD patients might be correlated with age, but not sex and Apo E genotypes.

Clinical Applications of Liquid Biopsy in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a common malignant tumor with high mortality and poor prognosis in the world. The low rate of early diagnosis, as well as the high risk of postoperative metastasis and recurrence, led to the poor clinical prognosis of HCC patients. Currently, it mainly depends on serum markers, imaging examination, and tissue biopsy to diagnose and determine the recurrence and metastasis of HCC after treatments. Nevertheless, the accuracy and sensitivity of serum markers and imaging for early HCC diagnosis are suboptimal. Tissue biopsy, containing limited tissue samples, is insufficient to reveal comprehensive tumor biology information and is inappropriate to monitor dynamic tumor progression due to its invasiveness. Thus, low invasive diagnostic methods and novel biomarkers with high sensitivity and reliability must be found to improve HCC detection and prediction. As a non-invasive, dynamic, and repeatable detection method, “liquid biopsy”, has attracted much attention to early diagnosis and monitoring of treatment response, which promotes the progress of precision medicine. This review summarizes the clinical applications of liquid biopsy in HCC, including circulating tumor cells (CTCs), circulating tumor DNA (ctDNA), and exosome in early diagnosis, prognostic evaluation, disease monitoring, and guiding personalized treatment.

[Clinical application of a prefabricated interocclusal recording cap for making interocclusal records of implant-supported fixed prostheses]

Objective: To use a self-developed, prefabricated cap for making interocclusal records in implant-supported fixed prosthetic treatment, and to evaluate its effect of clinical application and accuracy of transferring intra-oral intercuspal position. Methods: Series of prefabricated caps for occlusal recording of implant-supported fixed prostheses were designed based on the healing abutments, and fabricated with three-dimensional (3D) printing. According to the inclusion and exclusion criteria, 12 partially edentulous patients who visited the Department of Prosthodontics, Peking University School and Hospital of Stomatology between November 2020 and September 2021, had lost no fewer than 2 contiguous teeth in distal extension (Kennedy Class Ⅰ or Ⅱ), and had received implant placement 3 months ago were enrolled. Self-control study design was used. Two occlusal records of each included case were obtained by the following 2 methods: for the test group, appropriate prefabricated caps were used; and for the control group, polyvinyl siloxane occlusal record was directly set on the healing abutments. The working casts were mounted on the mechanical articulator using the 2 groups of occlusal records successively. Accuracy of occlusal relationship of the mounted casts was evaluated. Diagnostics test was performed to obtain the sensitivity and positive predictive value, which were determined in photographs by comparing the intra-oral occlusal contact points with those in the mounted casts, point-by-point. Virtual casts were taken by intraoral and extraoral scans in intercuspal position and imported to Geomagic Studio 2014. Then the root mean square values of occlusal clearance space between the upper and lower occlusal surfaces of remaining posterior teeth, and the deviations of the interocclusal position of the occlusal surfaces of the remaining teeth in the mandibular arches when superimposing the maxillary arches of the intraoral and extraoral scans were calculated. As a self-control design, paired t test was used. Results: Twelve participants were enrolled, including 3 men and 9 women aged (52.6±12.1) years, and 36 missing teeth. The prefabricated caps could fit on the healing abutments with good retention and stability. The sensitivity of the test group (0.73±0.14) was significantly better than that of control group (0.63±0.12,P<0.01), with no significant difference in positive predictive value between the 2 groups (P>0.05). The deviations of the interocclusal position of the occlusal surfaces of the remaining teeth were (357.0±140.2) μm for the test group, and (399.4±206.3) μm for the control group, with no significant difference between them (P>0.05). Conclusions: Interocclusal position record based on prefabricated cap in this study for implant-supported fixed prosthetic treatment can improve the consistency between the intra-oral occlusion and the occlusion in dental casts. This technique has good accuracy, clinical convenience and usability.

A FPGA-based adaptive differential current source for electrical impedance tomography

A high output impedance current source with a wide bandwidth is needed in electrical impedance tomography systems. Limitations appear mainly at higher frequencies and non-simple loads. In order to adjust the output current, the amplitude and phase are made to achieve the expected value automatically. A current source based on the field programmable gate array is designed. In this paper, we proposed a double DAC differential current source structure. By measuring the voltage of the sampling resistor in series with the load and using the proposed dynamic reference point demodulation algorithm, the actual current amplitude and phase on the load can be quickly obtained. Through the adaptive compensation module, the output current is adjusted to the expected value. The experimental results show that the output resistance of the current source can reach 10 MΩ and the output capacitance can be less than 0.8 pF in the frequency range of 10 kHz-1.28 MHz. At the same time, the current amplitude attenuation is less than 0.016%, and the phase error is less than 0.0025° after compensation. Therefore, the proposed current source achieves widebands, biocompatibility, and high precision.

[Study of sequential surgical guide assisting full arch immediate implant placement and provisionalization in patients with severe periodontitis]

To explore the technical process and the therapeutic effect of using sequential surgical guide with independent intellectual property rights assisting immediate implantation and restoration of the full arch, with the support from the periodontal splint for mobile supporting teeth, patients with severe periodontitis who planned to undergo immediate full arch implantation were recruited from August 2019 to December 2020 at the Department of Prosthodontics, Department of Periodontology, Department of Implantology and First Clinical Division, Peking University School and Hospital of Stomatology. Through the procedure of collecting preoperative maxillofacial data, making systematic diagnostic design, making periodontal splints fixation, producing surgical guide, and carrying out guided surgery for full arch immediate implantation, eight cases were included. By registering the postoperative cone-beam CT (CBCT) with the preoperative data, the difference between the actual three-dimensional position of the implants and the virtual design was observed, and the accuracy of the implant placement position guided by the sequential guide was statistically analyzed using SPSS 25.0 software. Analysis indicators include coronal and apical global displacement, coronal horizontal and vertical displacement, apical horizontal and vertical displacement, and angular deviation. Results revealed that the 8 patients [2 males and 6 females, aged (49.0±9.3) years (38-65 years)] of recruited cases included 7 cases of maxilla and 1 cases of mandible. A total of 48 implants, of which 44 implants were placed upright and 4 were placed tilted, 16 implants in the anterior region and 32 implants in the posterior region. No guide plate fracture or damage to important anatomical structures were reported. The overall displacement at the coronal point [(0.83±0.48) mm] and the global displacement at the apical point [(1.36±0.57) mm] were within the clinically acceptable safety range, and the horizontal displacement and vertical displacement at the coronal point, horizontal displacement and vertical displacement at the apical point, and the angle deviation of implants axial have no statistic significant difference in the anterior and posterior region (P>0.05). Periodontal splints combined with sequential surgical guides to assist patients with severe periodontitis for immediate full arch implantation and immediate restoration can expand the indications of guide assisted implant surgery. It meets the safety requirements in clinical applications.

[Evaluation of the fabrication deviation of a kind of milling digital implant surgical guides]

OBJECTIVE

To evaluate the deviation of digital implant surgical guides during fabrication process in the Organical Dental Implant (ODI) system.

METHODS

This study included two parts. The first part was the in vitro study. A resin block with a diagnostic template was used for the planning. After cone beam computed tomography (CBCT) scanning, a surgical guide with eight implants was virtually designed using the ODI system. The guide was milled by a 5-axial numerical controlled milling machine, and an optical scanning was taken to digitalize the guide to a standard tessellation language (STL) form. The STL data were then imported into an ODI software and registered with the original design. The deviation of the sleeves between the design and the STL was measured in the ODI software and set as the golden standard. Then the ODI examination table was used to measure the deviation of the guide during fabrication. Examiners A and B measured 10 times separately. The reliability and the validity of the examination table was calculated. The second part was the in vivo study: The deviation during fabrication of 12 guides designed and fabricated by the ODI system were measured using the examination table.

RESULTS

The standard deviation of the deviation measured using the examination table by examiners A and B were all below 0.40 mm (for the shell reference points) and 0.71 degree (for the angles). No significant difference was found between the two examiners for any implant sites. The result of the examination table was larger than that of the software for the shell reference point (t-test, P<0.05), but no significant difference was found for the angle deviation (t-test, P>0.05). The 45 implants positions in the 12 guides for the in vivo study were examined using the examination table. The deviations at the shell reference points were (1.06±0.29) mm (0.42-1.75 mm), and at the implant tip were (1.12±0.48) mm (0.41-2.44 mm). The angle deviations were (1.42±0.70) degree (0.29-2.96 degree).

CONCLUSION

Deviation is unavoidable during the fabrication process of the guides. The examination table of the ODI system is a reliable and valid tool to measure the deviation during fabrication of the ODI guides. More studies should be designed to research the relationship between the fabrication deviation and the implant insertion deviation.

[Analysis of the factors affecting the efficacy of (131)I remnant ablation in patients after thyroidectomy for papillary thyroid microcarcinoma]

Objective: To investigate the influential factors of efficacy of the first (131)I ablation therapy for thyroid remnant in papillary thyroid microcarcinoma (PTMC) patients after thyroidectomy. Methods: Eighty-nine PTMC patients who underwent twice (131)I ablation therapy and (131)I whole body follow-up scan ((131)I-WBS) within 5 to 8 months in our department from September 2007 to October 2016 were identified and enrolled in present study. Patients were divided into complete-ablation group and uncomplete-ablation group according to whether or not radioactivity was detected at the thyroid bed in (131)I-WBS. The χ(2) test and multi-variance Binary logistic regression were performed for the factors which might affect the therapeutic efficacy. Results: The first (131)I ablation therapy was successful in 41 of 89 patients (46.07%). Residual thyroid weight was found to be associated with therapeutic efficacy (P<0.05), while gender, age, surgical method, lesions'maximum diameter, with or without LN metastasis, with or without distant metastasis, time of operation from first (131)I treatment, lesions'number, thyroid stimulating hormone (TSH), thyroglobulin (Tg), the consistency of (131)I-WBS and (99)Tc(m)-pertechnatate, TNM stage, ATA risk, Tg/TSH ratio were not significant associated with therapeutic efficacy. Binary logistic regression analysis was performed in these respects and it indicated that residual thyroid weight and ATA risk were not statistically significant independent variable (P>0.05). Conclusions: Residual thyroid weight might affect efficacy of the first (131)I ablation therapy on thyroid remnant in PTMC patients after thyroidectomy, but it is not an independent factor. Multiple interrelated factors should be considered when predicting the efficacy of the first (131)I ablation therapy.

Supplemented Organic and Inorganic Selenium Affects Milk Performance and Selenium Concentration in Milk and Tissues in the Guanzhong Dairy Goat

Trace amounts of selenium (Se) are essential for several organisms, and deficiencies therein have adverse effects on growth, development, and reproduction; this is particularly significant in animals raised for milk and livestock production. To study the effect of Se on Guanzhong dairy goats, their diets were supplemented with different sources (inorganic or organic) and Se concentrations (0.2 or 0.4 mg Se/kg). A non-Se-fortified basal diet served as a negative control, and a sixth treatment group received both inorganic and organic Se sources (0.2 mg Se/kg diet each). Dietary Se supplementation increased milk production, with organic Se being more effective than inorganic Se. Selenium supplementation also increased Se concentration and glutathione peroxidase activity in whole blood, with organic Se more effective than inorganic Se at the same Se concentration. With increasing Se in diets, the Se content in milk increased markedly, reaching a plateau value at day 30 in all groups, and organic Se (0.4 mg/kg diet) had the best effect. In addition, dietary Se sources and concentrations markedly affected Se concentrations in different tissues and organs. Thus, organic Se supplementation of a basal diet at 0.4 mg/kg is practically applicable for Se-enriched milk and meat production in Guanzhong dairy goats.

Control of lactic acid production during hydrolysis and acidogenesis of food waste

Lactate accumulation occurs frequently during the hydrolysis and acidogenesis of food waste and produces an unfavorable substrate for anaerobic digestion. The objective of the present study was to reduce lactic acid production during the hydrolysis and acidogenesis of food waste in leachate bed reactor for establishment of the two-phase anaerobic digestion system. The results showed that the hydrolysis and acidogenesis of food waste in batch feeding mode underwent two consecutive stages, namely lactic acid fermentation and mixed acid fermentation. In the lactic acid fermentation stage, lactate constituted 74.4-96.8% of the total organic acids in the leachate. However in semi-continuous mode the content of lactate in the leachate could be reduced less than 0-2% for leach bed reactors operated at feeding loads of 50-150g/d although lactate accumulation occurred at a feeding load of 200g/d. Furthermore the organic acid shifted to acetate and butyrate, providing ideal substrates for anaerobic digestion.

[Expression of large tumor suppressor homolog 2 gene and its promotor methylation in oral squamous cell carcinoma]

Objective: To investigate the expression of large tumor suppressor homolog 2 (LATS2) gene and its promotor methylation in oral squamous cell carcinoma (OSCC). Methods: Reverse transcription-PCR (RT-PCR) and pyrosequencing were used to detect the mRNA and promotor methylation of LATS2 gene in 72 OSCC specimens and normal oral mucosa tissues. Western blotting was used to detect the LATS2 protein in six OSCC specimens and normal oral mucosa tissues. Results: All cases had expression of LATS2 mRNA in normal oral mucosa tissues, but the expression was down-regulated significantly, only 47% (34/72) in 72 cases of OSCC showed LATS2 mRNA expression. The expression was correlated with the degree of tumor differentiation and lymph node metastasis (P<0.05). The results of pyrosequencing show that 68% of promotor methylation (49/72) in 72 cases of OSCC. Furthermore, there was significant correlation between the mRNA and promotor methylation of LATS2 gene (χ(2)=16.980, P<0.01). All the six specimens had the low LATS2 protein expression. Conclusions: The promotor methylation of LATS2 gene may play an important role in the occurrence of OSCC.

Characterization of the Microbial Communities in the Ant Lion Euroleon coreanus (Okamoto) (Neuroptera: Myrmeleontidae)

Euroleon coreanus (Okamoto) is widely distributed in China, and the larval stage can be treated as traditional Chinese medicine. However, the host-bacterium relationship remains unexplored, as there is a lack of knowledge on the microbial community of ant lions. Hence, in the current study, we explored the microbial community of the larval ant lion E. coreanus using Illumina MiSeq sequencing. Results indicated that a total of 10 phyla, 126 genera, and 145 species were characterized from the second instars of E. coreanus, and most of the microbes were classified in the phylum Proteobacteria. Cronobacter muytjensii was the most abundant species characterized in the whole body and gut of E. coreanus, and the unclassified species in the genera Brevundimonas and Lactobacillus were relatively more abundant in the head and carcass. In addition, no Wolbachia-like bacteria were detected, whereas bacteria like Francisella tularensis subsp. Holarctica OSU18 and unclassified Rickettsiella were first identified in ant lion E. coreanus.

[Comparison of jaw thrust and trapezius squeezing test as indicators for laryngeal mask airway insertion in infants and young children]

OBJECTIVE

To compare the effectiveness of the jaw thrust and the trapezius squeezing test(TST) for laryngeal mask airway (LMA) insertion in infants and children under sevoflurane anesthesia.

METHODS

A total of 100 children aged from 6 month to 3 years, American Society of Anesthesiologists(ASA) Ⅰ-Ⅱ and undergoing minor operation were enrolled from January to June 2015 in Tianjin Children's Hospital. The patients were randomly divided into jaw thrusting group (Group J, n=50)and trapezius squeezing group(Group T, n=50). Anesthesia was induced with sevoflurane. When children's eyelash reflex lose, jaw thrust/trapezius squeeze was applied every 15 seconds.It's considered that the depth of anesthesia was not enough, and test reaction was positive if any movements of body, limbs or toes were found at the point of test. Sevoflurane should be keep on inhalation until negative test reaction was appeared. Then LMA was inserted immediately.The time required for the negative test, end-tidal sevoflurane concentrations (ETsev), the index of Narcotrend anesthesia monitor(NT), the occurrence of gross purposeful movements, coughing, gagging, breath-holding, laryngospasm or an SpO2 < 90% during LMA insertion in two groups of patients were observed and recorded. The condition of LMA insertion and the rate of successful insertion were evaluated. The blood pressure(BP), heart rate(HR) and SpO2 were also recorded before and after LMA insertion.

RESULTS

In group J and group T, the time required for the negative test was (2.31±1.03) vs (2.85±0.97)min(t=-2.462, P<0.05), ETsev was(3.25±1.02)% vs (3.81±0.87) %(t=-2.361, P<0.05), the depth of anesthesia NT index was(50.41±5.38) vs (41.32±4.92)(t=3.021, all P<0.05). All of above results were significantly different. The successful rate of the first attempt LMA insertion was 78% vs 100%(χ(2)=12.36 , P<0.01), respectively. The differences had statistical significance. The conditions of LMA insertion in group T were superior to those in group J. The incidences of gross purposeful movements, coughing, gagging, breath-holding and SpO2<90% during LMA insertion in group J were 20%, 16%, 10%, 14% and 8%, which were higher than those in group T (2%, 2%, 0, 2%, 0), the differences were significant(χ(2)=8.27, 5.98, 5.26, 4.89, 4.17, all P<0.05). No significant change in blood pressure, heart rate and SpO2 were found before and after inserting LMA in two groups.

CONCLUSION

The trapezius squeezing test is a superior indicator of adequate condition for LMA insertion compared to the jaw thrust in infants and young children under sevoflurane anesthesia.

Electronic structure of a new layered bismuth oxyselenide superconductor: LaO0.5F0.5BiSe2

LaO(0.5)F(0.5)BiSe(2) is a new layered superconductor discovered recently, which shows the superconducting transition temperature of 3.5 K. With angle-resolved photoemission spectroscopy, we study the electronic structure of LaO(0.5)F(0.5)BiSe(2) comprehensively. Two electron-like bands are located around the X point of the Brillouin zone, and the outer pockets connect with each other and form large Fermi surface around Γ and M. These bands show negligible k(z) dispersion, indicating their two-dimensional nature. Based on the Luttinger theorem, the carrier concentration is about 0.53 e(-) per unit cell, close to its nominal value. Moreover, the photoemission data and the band structure calculations agree very well, and the renormalization factor is nearly 1.0, indicating the electron correlations in this material are rather weak. Our results suggest that LaO(0.5)F(0.5)BiSe(2) is a conventional BCS superconductor without strong electron correlations.

Identification of critical TF-miRNA-mRNA regulation loops for colorectal cancer metastasis

To explore the potential cause of colorectal cancer metastasis, gene expression profiles, GSE21510, and miRNA expression profiles, GSE48074, were downloaded from the Gene Expression Omnibus database. Differentially expressed genes in metastatic colorectal and non metastatic colorectal cancer compared with the normal samples were identified via the limma package in R. The differentially expressed miRNAs in colorectal cancer samples with lymph node metastasis compared with those without lymph node metastasis were screened out by the some method. Differentially expressed genes that were upregulated in colorectal cancer samples with distant metastasis in comparison to that in samples without distant metastasis and normal samples were considered to play important roles in colorectal cancer metastasis. Functional enrichment analysis of these genes was conducted using the Database for Annotation, Visualization, and Integrated Discovery v6.7. Biological processes related to cell differentiation and cell proliferation were significantly enriched. TF (transcription factor)-miRNA-mRNA regulation loops were constructed by using the starBase and ChIPBase databases. Finally, six critical regulation loops were screened out. They were composed of two TFs, two miRNAs, and three mRNAs. Some of these TFs, mRNAs, or miRNAs have previously been identified as critical targets in colorectal cancer metastasis. Additionally, several new targets were identified in our study, which may be helpful to improve metastatic colorectal cancer treatment.

Morphological characteristics and developmental changes of the ovary in the tick Haemaphysalis longicornis Neumann

Haemaphysalis longicornis (Ixodida: Ixodidae) is an important vector of transovarially transmitted parasites of the genus Babesia (Piroplasmida: Babesiidae). In the present study, we investigated the morphological characteristics and developmental changes of the ovary of H. longicornis. We show that the ovary of H. longicornis has a single tubular structure and is surrounded by a tunica propria. There is a longitudinal groove along one side of the ovary. During feeding and after engorgement, great changes can be observed in the ovary of H. longicornis and two rapid growth phases can be detected. The number of major protein bands of the ovary is significantly increased from day 3 of feeding and reaches a maximum on the day of engorgement. Therefore, the great diversity of proteins in the ovaries of H. longicornis can facilitate the identification of new targets for vaccine development.

Protective effect of oleanolic acid against beta cell dysfunction and mitochondrial apoptosis: crucial role of ERK-NRF2 signaling pathway

Pancreatic beta cell dysfunction is a hallmark of diabetes. Our previous results have shown that oleanolic acid (OA) has anti-diabetic potential. However, there is little literature reporting the effect of OA on beta cell dysfunction. The present study was designed to investigate the protective effect of OA against lipotoxicity and the underlying mechanisms. Lepr (db/db) diabetic mice were subjected to fasting blood glucose measurement, intraperitoneal glucose tolerance test after the administration of OA for two weeks. Histopathological observation was conducted by HE staining and transmission electron microscopy assay. Pancreatic islets were isolated from db/db diabetic mice and C57BL/6J mice. Palmitic acid (PA) was used to induce lipotoxicity in vitro. Apoptosis was evaluated in pancreatic islets in diabetic mice and in isolated pancreatic islets and beta-TC3 cells by TUNEL assay. Cellular ATP content, mitochondrial function and redox balance were examined. Phosphorylation of c-Jun NH2-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK) and the activation of nuclear erythroid factor 2 p45-related factor 2 (Nrf2) signaling were evaluated by western blotting. In db/db mice, OA significantly protects beta cell function against lipotoxicity, evidenced by inhibition of apoptosis and improvement of glucose tolerance. In cells, OA administration may protect against PA-induced apoptosis and decrease of GSIS, in which process the activation of Nrf2 is essential. Once Nrf2 is activated, OA could induce GCLc expression, promote the production of GSH, and thus inhibit JNK phosphorylation and solid the antioxidant defense of mitochondria, leading to the inhibition of mitochondrial apoptosis. ERK signaling pathway is responsible for OA-induced activation of Nrf2 and the protective effect of OA. Overall, our study enhances the understanding of the protective effect of OA on beta cell and provides clues for further studies on the underlying mechanisms.

optiCall: a robust genotype-calling algorithm for rare, low-frequency and common variants

Motivation: Existing microarray genotype-calling algorithms adopt either SNP-by-SNP (SNP-wise) or sample-by-sample (sample-wise) approaches to calling. We have developed a novel genotype-calling algorithm for the Illumina platform, optiCall, that uses both SNP-wise and sample-wise calling to more accurately ascertain genotypes at rare, low-frequency and common variants.

Results: Using data from 4537 individuals from the 1958 British Birth Cohort genotyped on the Immunochip, we estimate the proportion of SNPs lost to downstream analysis due to false quality control failures, and rare variants misclassified as monomorphic, is only 1.38% with optiCall, in comparison to 3.87, 7.85 and 4.09% for Illuminus, GenoSNP and GenCall, respectively. We show that optiCall accurately captures rare variants and can correctly account for SNPs where probe intensity clouds are shifted from their expected positions.

Availability and implementation: optiCall is implemented in C++ for use on UNIX operating systems and is available for download at http://www.sanger.ac.uk/resources/software/opticall/.

Contact:optiCall@sanger.ac.uk

Genome-wide association study of major depressive disorder: new results, meta-analysis, and lessons learned

Major depressive disorder (MDD) is a common complex disorder with a partly genetic etiology. We conducted a genome-wide association study of the MDD2000+ sample (2431 cases, 3673 screened controls and >1 M imputed single-nucleotide polymorphisms (SNPs)). No SNPs achieved genome-wide significance either in the MDD2000+ study, or in meta-analysis with two other studies totaling 5763 cases and 6901 controls. These results imply that common variants of intermediate or large effect do not have main effects in the genetic architecture of MDD. Suggestive but notable results were (a) gene-based tests suggesting roles for adenylate cyclase 3 (ADCY3, 2p23.3) and galanin (GAL, 11q13.3); published functional evidence relates both of these to MDD and serotonergic signaling; (b) support for the bipolar disorder risk variant SNP rs1006737 in CACNA1C (P=0.020, odds ratio=1.10); and (c) lack of support for rs2251219, a SNP identified in a meta-analysis of affective disorder studies (P=0.51). We estimate that sample sizes 1.8- to 2.4-fold greater are needed for association studies of MDD compared with those for schizophrenia to detect variants that explain the same proportion of total variance in liability. Larger study cohorts characterized for genetic and environmental risk factors accumulated prospectively are likely to be needed to dissect more fully the etiology of MDD.

Beneficial effects of jejunal continuity and duodenal food passage after total gastrectomy: a retrospective study of 704 patients

AIM

To evaluate effects of reconstruction procedures on post-operative outcomes and nutritional status after total gastrectomy.

METHODS

The study group comprised 704 consecutive patients with gastric cancer who underwent total gastrectomy between December 1985 and December 2003. Six alimentary reconstruction procedures were performed, including jejunal continuity [Braun, modified Braun I and II and functional jejunal interposition (FJI)] and jejunum transection ["P" Roux-en-Y and "P" jejunal interposition (PJI)]. The duodenal food passage was maintained only by FJI and PJI. We evaluated the time interval to restore food intake after surgery and the incidence of complications and nutritional status for 12 months.

RESULTS

Patients who received jejunum transection required 7.8+/-2.5 days and 11.9+/-4.9 days to restore liquid and semi-liquid food intake, respectively, which reduced to 3.9+/-2.1 days for liquid and 7.9+/-3.9 days for semi-liquid food intake by jejunum continuity. The incidence rates of reflux esophagitis and Roux-en-Y syndrome in patients receiving jejunum transection were 23.5% and 42.4%, respectively, which were decreased to 9.35% and 14.7%, respectively, by jejunal continuity. Furthermore, prognostic nutrition index score of patients receiving the procedures maintaining duodenal food passage (52.9+/-10.9) was higher than that of patients without the duodenal food passage (46.7+/-8.2).

CONCLUSION

Jejunal continuity and duodenal food passage showed beneficial effects on clinical outcomes after surgery. Among these six procedures, FJI was the only procedure to combine the benefits of jejunal continuity and maintaining the duodenal food passage, indicating that FJI has potential clinical application to improve the quality of patient's life after total gastrectomy.

Effect of dimethyl sulfoxide on post-thaw viability assessment of CD45+ and CD34+ cells of umbilical cord blood and mobilized peripheral blood

BACKGROUND

The effect of dimethyl sulfoxide (Me2SO) on enumeration of post-thaw CD45+ and CD34+ cells of umbilical cord blood (HPC-C) and mobilized peripheral blood (HPC-A) has not been systematically studied.

METHODS

Cells from leukapheresis products from multiple myeloma patients and umbilical cord blood cells were suspended in 1, 2, 5, or 10% Me2SO for 20 min at 22 degrees C. Cells suspended in Me2SO were then immediately assessed or assessed following removal of Me2SO. In other samples, cells were suspended in 10% Me2SO, cooled slowly to -60 degrees C, stored at -150 degrees C for 48 h, then thawed. The thawed cells in 10% Me2SO were diluted to 1, 2, 5, or 10% Me2SO, held for 20 min at 22 degrees C and then immediately assessed or assessed after the removal of Me2SO. CD34+ cell viability was determined using a single platform flow cytometric absolute CD34+ cell count technique incorporating 7-AAD.

RESULTS

The results indicate that after cryopreservation neither recovery of CD34+ cells nor viability of CD45+ and CD34+ cells from both post-thaw HPC-A and HPC-C were a function of the concentration of Me2SO. Without cryopreservation, when Me2SO is present recovery and viability of HPC-C CD34+ cells exposed to 10% Me2SO but not CD45+ cells were significantly decreased. Removing Me2SO by centrifugation significantly decreased the viability and recovery of CD34+ cells in both HPC-A and HPC-C before and after cryopreservation.

DISCUSSION

To reflect the actual number of CD45+ cells and CD34+ cells infused into a patient, these results indicate that removal of Me2SO for assessment of CD34+ cell viability should only be performed if the HPC are infused after washing to remove Me2SO.

Linear correlation between fractal dimension of EEG signal and handgrip force

Fractal dimension (FD) has been proved useful in quantifying the complexity of dynamical signals in biology and medicine. In this study, we measured FDs of human electroencephalographic (EEG) signals at different levels of handgrip forces. EEG signals were recorded from five major motor-related cortical areas in eight normal healthy subjects. FDs were calculated using three different methods. The three physiological periods of handgrip (command preparation, movement and holding periods) were analyzed and compared. The results showed that FDs of the EEG signals during the movement and holding periods increased linearly with handgrip force, whereas FD during the preparation period had no correlation with force. The results also demonstrated that one method (Katz's) gave greater changes in FD, and thus, had more power in capturing the dynamic changes in the signal. The linear increase of FD, together with results from other EEG and neuroimaging studies, suggest that under normal conditions the brain recruits motor neurons at a linear progress when increasing the force.

Microinjection of glutamate into dorsal motor nucleus of the vagus excites gallbladder motility through NMDA receptor - nitric oxide - cGMP pathway

We have reported that both glutamate and nitric oxide (NO) participated in the regulation of gallbladder motility in dorsal motor nucleus of the vagus (DMV). The aim of this study is to investigate the type of receptor in DMV that mediates the excitatory effect of glutamate on gallbladder motility and the correlation between the glutamate and NO. A frog bladder connected with a force transducer was inserted into the gallbladder to record the change of gallbladder pressure. Glutamate (65 mmol L(-1), 100 nL) microinjected into DMV significantly increased the strength of gallbladder phasic contraction. This effect was abolished by ketamine (180 mmol L(-1), 100 nL), the specific N-methyl-d-aspartic acid (NMDA) receptor antagonist, but was not influenced by 6-cyaon-7-nitroquinoxaline-2,3-(1H,4H)-dione (CNQX) (180 mmol L(-1), 100 nL), the non-NMDA ionotropic receptor antagonist. N(G)-nitro-l-arginine-emthyl (l-NAME) (1 mol L(-1), 100 nL), the nitric oxide synthase (NOS) inhibitor, reversed the excitatory effect of glutamate on gallbladder motility. Microinjection of sodium nitroprusside (SNP), the NO donor, into DMV enhanced the gallbladder motility, and this effect was not modulated by ketamine. Microinjection of NMDA (5 mmol L(-1), 100 nL) increased the strength of gallbladder phasic contraction, and this effect was attenuated by methylene blue (100 mmol L(-1), 100 nL), the soluble guanylate cyclase inhibitor. These results suggest that glutamate regulate the gallbladder motility through the NMDA receptor - NO - cGMP pathway in DMV.

The compound DATEM inhibits respiratory syncytial virus fusion activity with epithelial cells

The effect of diacetyltartaric acid esters of mono and diglycerides (DATEM) on fusion of respiratory syncytial virus (RSV) with HEp-2 cells was studied using the R18 fluorescence dequenching fusion assay. At DATEM concentrations less than 2.0 microg/ml, the inhibition of fusion increased with the concentration of DATEM. At 2 microg/ml of DATEM, the fusion was suppressed by 80-90%. Studies examining possible mechanism of fusion-inhibition indicated that DATEM was likely adsorbed onto lipid membranes of both viral envelope and target cell membranes. Quantitative measurements of DATEM adsorption onto membranes were also performed using lipid monolayers and vesicles. The surface pressure of lipid monolayer formed at the air/aqueous interface increased as the concentration of DATEM in the monolayer subphase increased, suggesting that DATEM was inserted into the monolayer. As the concentration of DATEM in vesicle suspensions increased, electrophoretic mobility of initially uncharged lipid vesicles also increased, reflective of increased negative charge at vesicle surfaces. These results strongly suggest that the insertion of DATEM onto membranes inhibited viral fusion. DATEM may prove to be effective in limiting the infectivity of RSV by interference with the fusion of the viral envelope with target cell membranes.

Functional magnetic resonance imaging before and after ventriculoperitoneal shunting for hydrocephalus--case report

A 70-year-old man with hydrocephalus was examined with functional magnetic resonance (fMR) imaging before and after ventriculoperitoneal shunting. Preoperatively, activation by right hand exercise revealed only a slight signal increase in the peri-rolandic area. However, 3 months after ventriculoperitoneal shunting, a significant signal increase was observed. fMR imaging may detect activity-related improvement of cerebral blood flow responses in patients with hydrocephalus after surgical treatment.

[Studies of hypoxic rat brain mitochondrial transcription activity in vitro]

AIM

To explore the effects of acute and chronic hypoxia on brain mitochondrial transcription activity in vitro of rats.

METHODS

Animal grouping: Wistar rats were randomized into acute hypoxic group (AH), chronic hypoxic group (CH) and the control. Mitochondrial transcription activity in vitro was measured in each group respectively as well as mitochondrial F0F1-ATPase activity, and effects of environmental ATP concentration on mitochondrial transcription activity in vitro was observed.

RESULTS

Brain mitochondrial transcription activity and F0F1-ATPase activity were marked depressed in AH while partly reversed in CH, and they were linearly related. Mitochondrial transcription activity in vitro was affected by ATP concentration diphasely.

CONCLUSION

Acute hypoxia may impair brain mitochondria energy metabolism by way of depressing mitochondrial transcription and then partially recover during chronic hypoxia. And mitochondrial transcription in vitro might be precisely regulated by ATP concentration.

Relationship between muscle output and functional MRI-measured brain activation

The relationship between functional MRI (fMRI)-measured brain signal and muscle force and or electromyogram (EMG) is critical in interpreting fMRI data and understanding the control mechanisms of voluntary motor actions. We designed a system that could record joint force and surface EMG online with fMRI data. High-quality force and EMG data were obtained while maintaining the quality of the fMRI brain images. Using this system, we determined the relationship between fMRI-measured brain activation and handgrip force and between fMRI-measured brain signal and EMG of extrinsic finger muscles. Ten volunteers participated in the experiments (only seven subjects' data were analyzed due to excessive noise in the fMRI data of three subjects). The participants exerted 20%, 35%, 50%, 65%, and 80% of the maximal force. During each contraction period, handgrip force, surface EMG of the finger flexor and extensor muscles, and fMRI brain images were acquired. The degree of muscle activation (force and EMG) was directly proportional to the amplitude of the brain signal determined by fMRI in the entire brain and in a number of motor function-related cortical fields, including primary motor, sensory regions, supplementary motor area, premotor, prefrontal, parietal and cingulate cortices, and cerebellum. All the examined brain areas demonstrated a similar relationship between the fMRI signal and force. A stronger fMRI signal during higher force indicates that more cortical output neurons and/or interneurons may participate in generating descending commands and/or processing additional sensory information. The similarity in the relationship between muscle output and fMRI signal in the cortical regions suggests that correlated or networked activation among a number of cortical fields may be necessary for controlling precise static force of finger muscles.

Skilled finger movement exercise improves hand function

BACKGROUND

Aging is accompanied by a marked decline in muscle strength and ability to maintain steady submaximal force. Studies have shown that exercise programs can improve age-related regression of hand function in elderly individuals. The purpose of this study was to train elderly subjects to perform skilled finger movements and to evaluate the changes in hand function involving skillful use of finger pinch.

METHODS

Grip strength, maximum pinch force (MPF), steadiness of pinch force at 5%, 10%, and 20% MPF, M wave, and Hoffman (H) reflex were measured. Fourteen elderly subjects were trained with skilled finger movements, and their performance involving finger pinch was measured.

RESULTS

Compared with untrained elderly subjects, the trained older adults significantly (p <.05) improved their ability to control submaximal pinch force, to maintain a steady hand posture, and to relocate a small object quickly with finger grip. The amplitude of H reflex increased significantly for the trained group.

CONCLUSIONS

Skilled finger movement training improves the ability to control submaximal pinch force, hand steadiness, and manual speed in elderly subjects; these improvements may be due to training-induced adaptations in the central and peripheral nervous systems.

[Allografting for massive bone defect: bone and soft tissue reconstruction and postoperative rehabilitation]

OBJECTIVE

To evaluate the results of limb function and the methods of bone and soft tissue reconstruction of patients treated with allografting.

METHODS

From May 1992 to January 1999, 90 patients suffered from bone malignant tumor were treated with allografting in different methods of internal fixations. The average follow-up was 37.5 months. The limb postoperative function, complications related to different surgical methods were compared according to Enneking evaluation system.

RESULTS

Skin necrosis, infection, non-union, fracture of allograft were the main complications which affect patients' limb postoperative functions. Of the 90 fresh-frozen allografting procedures, the final results of operation showed that hip joints and knee joints were better than the shoulder joints. More than 80% of the patients treated with interlocked intramedullary nail and allograft-prosthesis combination led to an over-all result that was excellent and good. Interlocked intermedullary nail was of recommended method of internal fixation. Early exercises of operative limbs could promote function recovery.

CONCLUSION

Using of interlocked intramedullary nail and allograft-prosthesis combination are of recommended operation method and can be applied with better results, and early exercises of operative limbs will lead to better functions.

DNA-binding and photocleavage studies of cobalt(III) mixed-polypyridyl complexes containing 2-(2-chloro-5-nitrophenyl)imidazo [4,5-f][1,10]phenanthroline

The ligand 2-(2-chloro-5-nitrophenyl)imidazo[4,5-f][1,10]phenanthroline(CNOIP) and its complexes [Co(bpy)(2)(CNOIP)](3+) (1) and [Co(phen)(2)(CNOIP)](3+) (2) (bpy=2,2'-bipyridine; phen=1,10-phenanthroline) have been synthesized and characterized. Binding of the two complexes with calf thymus DNA has been investigated by spectroscopic methods, cyclic voltammetry, viscosity, and electrophoresis measurements. The experimental results indicate that both complexes bind to DNA through an intercalative mode. In comparison with their parent complexes containing PIP ligand (PIP=2-phenylimidazo[4,5-f][1,10]phenanthroline), the introduction of NO(2) and Cl groups to the PIP ligand decreased the binding affinity of complexes 1 and 2 to CT DNA. Both complexes have also been found to promote the photocleavage of plasmid pBR 322 DNA, the hydroxyl radical (OH*) is suggested to be the reactive species responsible for the cleavage.

[Effect of nucleus raphe obscurus on myoelectric activity of sphincter of Oddi in rabbits]

The aim of the present study was to investigate the role of nucleus raphe obscurus (NRO) in regulating the motility of sphincter of Oddi (SO). After fasting about l8~24 h, the rabbits were anesthetized with urethane (1.0 g/kg), and the myoelectric signals of SO were induced by a pair of copper electrodes inserted into the subsera. The results of microinjection of various drugs into NRO are as follows. After glutamate (340 mmol/L, 0.1 microl) was injected, activity of SO was excited. With microinjection of GABA (1 mol/L,0.1 microl), the spike burst of SO was inhibited. Following microinjection of ketamine (180 mmol/L, 0.1 microl), a kind of N-methyl-D-aspartate (NMDA) receptor antagonist, SO motility was inhibited and the effect of glutamate was abolished. Injection of 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) (2 mmol/L, 0.1 microl), a non-NMDA receptor antagonist, also excited the myoelectric activity of SO, but did not inhibit the effect of glutamate. The effect of glutamate was abolished by intravenous injection of atropine (0.2 mg/kg) or bilateral vagotomy, but not by injection of phentolamine (1.5 mg/kg) or propronalol (1.5 mg/kg), or by transection of the spinal cord. The above results indicate that NRO mediation of SO activity is due to the effect of glutamate on the NMDA receptors in the nucleus, the output of which is sent through vagal nerve and peripheral M cholinergic receptor to exert excitation of gallbladder motility.

Effect of a rippling mode on resonances of carbon nanotubes

A recent study determined the Young's modulus of carbon nanotubes by measuring resonance frequency and using the modulus-frequency relation resulting from the linear vibration theory. It leads to the report that the Young's modulus decreases sharply, from about 1 to 0.1 TPa with the diameter D increasing from 8 to 40 nanometers, and the investigators attributed this decrease to the emergence of an unusual bending mode during the measurement that corresponds to rippling on the inner arc of the bent nanotubes. The nonlinear analysis presented in this paper that captures the rippling mode suggests that the effective Young's modulus can indeed decrease substantially with increasing diameter, and that the results from the classical linear theory may be invalid in such measurements.

Effects of metal ions on simultaneous production of glucose oxidase and catalase by Aspergillus niger

The effects of various metal ions on the simultaneous production of glucose oxidase and catalase by Aspergillus niger were investigated. Calcium carbonate induced synthesis of both enzymes. The induction of calcium carbonate was accompanied by a metabolic shift from the glycolytic pathway (EMP, Embden-Meyerhof-Parnas) to direct oxidation of glucose by glucose oxidase. The time course of the biosynthesis of both enzymes is reported. The logistic model was in good agreement with the experimental growth results. The production of both enzymes was growth-associated. Finally, a model of growth and product formation was also proposed.

[A study on the expression of human leptin in the mammary glands of transgenic mice]

Human leptin expressed by E. coli had been used to treat human obesity in American and scientists had achieved good effects, the researchers here wanted to know whether human leptin can be expressed in the mammary glands of transgenic animas. In this study, human leptin gene about 1.0 kb, the terminator of rabbit whey acid protein gene (rWAP) about 0.2 kb and the promoter including the distal upstream region and part of the first exon of rWAP gene about 6.3 kb were used to construct a expression vector. Before we did the subclonings, the sequences of the human leptin gene were sequenced by ABI377 DNA Sequencer, the results showed that the fragment of human leptin gene included the last nine base pairs of the first exon, the complete sequences of the second exon(172 bp) and parts of the third exon(including part of the encoding sequences and part of the 3' untranslated region). The final expression vector was digested with NotI and a fragment of 7.5 kb was collected and dissolved in TE(10 mmol/L Tris.Cl, pH7.4; 0.1 mmol/L EDTA) for later microinjection. The concentration of DNA was about 2 micrograms/mL, the copy number in 1 mL was about 2.4 x 10(11), every 1 to 2 pL of the prepared DNA solution was microinjected into the mouse embryos at pronucleus stage. After standard microinjection procedures, 48 live mice were obtained. The tails of the mice were cut(about 0.1 g) at four weeks of age, genomic DNA was extracted and digested completely with EcoRI, two were confirmed to be transgenic mice(both were female) by Southern hybridization using DIG labeled human leptin gene as probe, transgenic rate among the mice born was about 4% (2/48). The two female transgenic mice(2# and C3) were mated with nontransgenic male mice. The two founder transgenic mice were segregated with their baby mice for at least three hours at the fifth day after parturition and were milked by intraperitoneal injection of 0.3 IU of oxytocin and udder massage. SDS-PAGE was used to analyze whether there were expression of human leptin in the milk of the two founder transgenic mice with the milk of non-transgenic mouse at fifth day after parturition as control. SDS-PAGE results showed that compared with the control there was a new band in both of the founder transgenic mice milk, and its molecular weight was about 16 kD, which was quite similar with that of the human leptin. The researchers estimated that the expression level of this protein in the milk of the transgenic mice was about 1-2 mg/mL.

[The vagus nerve coordinates the motion of gallbladder and sphincter of Oddi in the interdigestive period in rabbits]

AIM

To investigate the effect of vagus nerve on coordinating the motion of gallbladder (GB) and sphincter of Oddi (SO) in the interdigestive period in rabbits.

METHODS

Fasted for 15 h-18 h, but allowed to drink water, the rabbib were anesthetized with urethane (1.0 mg/kg, i.v.). In order to measure GB pressure, a frog bladder filled with normal saline was put into GB and connected to a transducer (TP-200T). Myoelectric signals of SO was recorded by a pair of copper electrodes.

RESULTS

In the interdigestive period, phasic contractions of GB (PCGB) and clusters of spike potentials of SO (CSPSO) was 1:1 correlated (Y = 0.962X + 0.587, r = 0.982, P < 0.01). That is, every PCGB was accompanied by one CSPSO. Microinjection of thyrotropin-releasing hormone (TRH, 0.8 nmol, 1 microliter) or monosodium glutamate (MSG, 2 mumol, 1 microliter) into dorsal vagal complex (DVC) enhanced the motility of GB and SO, and the 1:1 temporal relation between PCGB and CSPSO still existed. Vagotomy or intravenous injection of atropine inhibited the PCGB and the spike potentials of SO, and the 1:1 correlation between PCGB and CSPSO disappeared. The spike bursts of SO did not respond to the artificial rise of gallbladder pressure.

CONCLUSION

In the interdigestive period in rabbits, gallbladder and SO contract and relax rhythmically and simultaneously. This eoordinated motion between GB and SO is controlled by DVC via vagus nerve and peripheral M receptors.

The human factor IX gene as germline mutagen test: samples from Mainland China have the putatively endogenous pattern of mutation

Germline mutations are the major source of genetic variation that allows a species to evolve over time but at the cost of Mendelian disease and genetic predisposition to multifactorial diseases. Previous analyses have revealed that the pattern of germline mutations in the factor IX gene (F9) is similar among a variety of ethnically and geographically diverse populations and compatible with the ancient pattern that has shaped the mammalian genome. Here, we compare the pattern of germline mutation in a population of hemophilia B patients from Mainland China (n=66) to that in U.S. Caucasians, Blacks, and Mexican Hispanics and stratify by disease severity and ethnicity. The similar pattern of germline mutation in all ethnic groups studied to date provides additional data compatible with the inference that endogenous processes predominate in germline mutations.

Simultaneous measurement of human joint force, surface electromyograms, and functional MRI-measured brain activation

Functional magnetic resonance imaging (fMRI) has been increasingly used in studying human brain function given its non-invasive feature and good spatial resolution. However, difficulties in acquiring data from peripheral (e.g. information from muscle) during fMRI studies of motor function hinder interpretation of fMRI data and designing more sophisticated investigations. Here we describe a system that was designed to concurrently measure handgrip force, surface electromyograms (EMG) of finger flexor and extensor muscles, and fMRI of human brain. The system included a pressure transducer built in a hydraulic environment, a heavily shielded EMG recording element, and a visual feedback structure for online monitoring of force and/or EMG signal, by the subject positioned in the scanner during an fMRI experiment. System evaluation and subsequent fMRI motor function studies have indicated that by using this system, high quality force and EMG signals can be recorded without sacrificing the quality of the fMRI data.

Relationship between motor activity-related cortical potential and voluntary muscle activation

The purpose of this study was to investigate the relationship between EEG-derived motor activity-related cortical potential (MRCP) and voluntary muscle activation. Eight healthy volunteers participated in two experimental sessions. In one session, subjects performed isometric elbow-flexion contractions at four intensity levels [10%, 35%, 60%, and 85% maximal voluntary contraction (MVC)]. In another session, a given elbow-flexion force (35% MVC) was generated at three different rates (slow, intermediate, and fast). Thirty to 40 contractions were performed at each force level or rate. EEG signals were recorded from the scalp overlying the supplementary motor area (SMA) and contralateral sensorimotor cortex, and EMG signals were recorded from the skin surface overlying the belly of the biceps brachii and brachioradialis muscles during all contractions. In each trial, the force was used as the triggering signal for MRCP averaging. MRCP amplitude was measured from the beginning to the peak of the negative slope. The magnitude of MRCP from both EEG recording locations (sensorimotor cortex and SMA) was highly correlated with elbow-flexion force, rate of rising of force, and muscle EMG signals. These results suggest that MRCP represents cortical motor commands that scale the level of muscle activation.