[Design and application of static progressive ankle foot orthosis]

The scar contracture of Achilles tendon in burn patients after operation is easy to cause " foot drop" , which leads to ankle dorsiflexion dysfunction. To solve this problem, the authors designed and made a static progressive ankle foot orthosis. The foot support part and the crus support part of the orthotic device are connected by rivets, and the distal end of the foot support part and the proximal end of the crus support part are pulled by the traction belt on both sides, gradually improving the ankle dorsiflexion function. This static progressive ankle foot orthosis is simple, practical, cost-effective, and worthy of clinical promotion.

[Nursing strategies for the facial skin injuries caused by wearing medical-grade protective equipment]

For effective resistance to virus attack and infection and reducing virus transmission chance, it is extremely important for the medical staff and related workers to have their own safe protection. The paper summarizes the occurrence causes, common locations, and prevention ways about the device related pressure ulcers on the face resulted from wearing medical-grade protective equipment for a long working time. The paper proposes the prevention and nursing strategies for device related pressure ulcers and other related skin injuries during application of medical-grade protective equipment. The paper aims to provide reference for the prevention and nursing of device related pressure ulcers and related skin diseases for clinical medical staff, especially to the respectable personnel in front line of fighting against coronavirus disease 2019.

[Application of low temperature thermoplastic plate combined with special abdominal band in fixing abdominal pedicled flap for repairing 17 patients with deep electric burn wounds in hands]

If the abdominal pedicled flaps are not well fixed after repair of deep electric burn wounds in hands, many problems such as poor blood supply may occur. In order to solve the above problems, we designed and manufactured the individualized low temperature thermoplastic plate combined with special abdominal band to fix abdominal pedicled flaps for repairing of 17 patients (12 males and 5 females, aged 2-35 years) with deep electric burn wounds in hands from February 2016 to August 2018, and achieved the desired results. The shoulder joint, elbow joint, and wrist joint were fixed by low temperature thermoplastic plate according to the 1/2 circumference of the patient's side chest and upper arm, and the braking of wrist joint and elbow joint was strengthened by special abdominal band. Application of the combined method of fixing abdominal pedicled flaps in repairing deep electric burn wounds in hands has high success rate of flap transplantation. It is simple to make and practical, and worthy of clinical promotion.

[Influences of follow-up methods on rehabilitation and compliance of patients with severe scar after burns]

Objective: To observe the influences of different follow-up methods on rehabilitation and compliance of patients with severe scar after burns. Methods: From January 2012 to May 2016, medical records of 116 patients with severe scar after burns who were admitted to our unit, discharged after wound healing and conforming to the criteria, were retrospectively analyzed. They were divided into face-to-face follow-up group [n=59, 45 males and 14 females, aged (36±9) years] and routine follow-up group [n=57, 44 males and 13 females, aged (35±9) years] based on different follow-up methods they received. On the day of discharge and in post discharge month (PDM) 1, 3, and 6, the Vancouver Scar Scale (VSS) was used to evaluate the hypertrophic scar in joints, Activities of Daily Living (ADL) scale was used to evaluate the disability of patients in the 2 groups. In PDM 1, 3, and 6, Medical Compliance Behavior Questionnaire was used to investigate the medical compliance behaviors of patients in the 2 groups. Data were processed with chi-square test, t test with Bonferroni correction, and analysis of variance for repeated measurement. Results: (1) The VSS score of patients in face-to-face follow-up group on the day of discharge was (11.1±0.7) points, which was close to (11.7±0.7) points of routine follow-up group (t=2.021, P>0.05). The VSS scores of patients in face-to-face follow-up group in PDM 1, 3, and 6 were (10.5±0.6), (8.6±0.7), and (4.7±0.5) points, which were significantly lower than (11.4±0.7), (10.9±1.0), and (9.4±0.8) points of routine follow-up group respectively (t=2.034, 2.033, 2.042, P<0.05 or P<0.01). (2) The ADL score of patients in face-to-face follow-up group on the day of discharge was close to that of routine follow-up group (t=1.781, P>0.05). The ADL scores of patients in face-to-face follow-up group in PDM 1, 3, and 6 were higher than those of routine follow-up group respectively (t=9.683, 8.584, 9.772, P<0.01). (3) The compliance rates of consisted rehabilitation, reasonable diet, and timing consultation of patients in face-to-face follow-up group were better than those of routine follow-up group respectively (χ(2)=19.015, 13.251, 8.652, P<0.01). Conclusions: Compared with routine follow-up by phone, face-to-face follow-up can do better in evaluating the scar condition and ADL of patients with severe scar after burns, and improve the medical compliance rates of patients, which is worthy of clinical promotion.

[Observation on the effects of multidisciplinary comprehensive intervention in integrated treatment of patients with extremely severe burns]

Objective: To explore the effects of multidisciplinary comprehensive intervention in integrated treatment of patients with extremely severe burns. Methods: One hundred and ten patients hospitalized in our center from July 2013 to August 2017 met the criteria for inclusion in this study, and their medical records were retrospectively analyzed. According to the medical model at that time, 56 patients hospitalized from July 2013 to July 2015 received routine comprehensive treatment led by doctors, and they were included in the conventional intervention group. From August 2015 to August 2017, 54 patients were treated with integrated multidisciplinary interventions performed by a team consisting of physicians, intensive care nurses, burn nurses, intravenous infusion nurses, wound stoma nurses, and rehabilitation therapists, and they were included in the integrated intervention group. Acute Physiological and Chronic Health Assessment Ⅱ (APACHE Ⅱ) scores on admission and 4 weeks after treatment, incidences of pressure injury, wound sepsis, lung infection, and catheter-related infection during hospitalization, length of stay in intensive care unit (ICU) and total length of hospital stay, and Abbreviated Burn Specific Health Scale (BSHS-A) scores at discharge and 3 months after discharge were analyzed. Data were processed with t-test and chi-square test. Results: The APACHE Ⅱ scores of patients in the two groups were close on admission (t=0.573, P>0.05). Four weeks after treatment, the APACHE Ⅱ scores of patients in the two groups were obviously lower than those on admission within the same group (t=5.697, 4.853, P<0.01), and the score of the integrated intervention group was obviously lower than that of the conventional intervention group (t=2.170, P<0.05). No pressure injury was observed in patients of any group during hospitalization. The incidences of wound sepsis, lung infection, and catheter-related infection of patients in the integrated intervention group were 18.5% (10/54), 3.7% (2/54), and 9.3% (5/54), respectively, significantly lower than 42.9% (24/56), 21.4% (12/56), and 26.8% (15/56) of the conventional intervention group, χ²=4.073, 6.075, 3.962, P<0.05. The length of stay in ICU of patients in the integrated intervention group was (50±5) d, obviously shorter than (62±4) d of the conventional intervention group (t=2.852, P<0.01). The total length of hospital stay of patients in the integrated intervention group was (115±8) d, obviously shorter than (140±7) d of the conventional intervention group (t=16.885, P<0.01). At discharge and 3 months after discharge, the scores of BSHS-A, physical function, psychological function, and general health status of 50 patients in the integrated intervention group were significantly higher than those of 48 patients in the conventional intervention group (t=2.886, 3.126, 2.416, 2.544, 2.033, 3.471, 2.588, 2.210, P<0.05 or P<0.01), while the scores of social function of patients in the two groups were close (t=1.570, 1.350, P>0.05). Conclusions: Integrative treatment of patients with extremely severe burns by multidisciplinary comprehensive intervention can significantly alleviate the severity of burns, reduce the incidences of wound sepsis, lung infection, and catheter-related infection, shorten the length of stay in ICU and total length of hospital stay, and improve the quality of life.

[A case of schwannoma in cervical trachea]

Primary tracheal schwannoma is rare. It is easy to be misdiagnosed as bronchitis, asthma due to the lack of special symptom. Diagnosis of schwannoma depends on a comprehensive examination. Surgery is the only effective mean. Here we reported a 17-year-old male, who suffered from cough for 10 months. A variety of tests confirmed that he had schwannoma. There is no significant change after tumor resection via rigid bronchoscope since two years ago.

Robust half-metallic ferromagnetism and curvature dependent magnetic coupling in fluorinated boron nitride nanotubes

The fluorinated boron nitride (F-BN) nanostructures are found to be fully spin polarized and half-metallic by means of first-principles calculations based on the Heyd-Scuseria-Ernzerhof hybrid functional. It is found that the full spin polarization and 1 μB local moment in F-BN nanotubes are independent of tube radius and it is also robust in planar ribbons and sheets. The long-ranged ferromagnetic coupling between local moments decreases with decreasing tube radius. This suggests that F-BN systems with small local curvatures could be more easily experimentally observed and have greater potential applications in spin devices.

Phytoremediation of soils contaminated with phenanthrene and cadmium by growing willow (Salix × aureo-pendula CL 'j1011')

To assess the phytoremediation potential of an autochthonous willow (Salix × aureo-pendula CL 'J1011') for phenanthrene (PHE)-contaminated soils and PHE-cadmium (PHE-Cd) co-contaminated soils, we conducted field experiments in the lower reaches of the Yangtze River, China. Ethylenediaminetetraacetic acid (EDTA) and ethyl lactate were tested for individual and combined effects on the phytoremediation efficiency. For PHE-contaminated soils, willow plus ethyl lactate resulted in significant removal of PHE from soils after 45 days, and the PHE concentration in the shoots was significantly higher with than without ethyl lactate. For PHE-Cd co-contaminated soils, both willow plus EDTA and willow plus EDTA and ethyl lactate led to a significant decrease in the concentrations of PHE and Cd in the soils after 45 days, whereas willow alone did not. The PHE and Cd concentrations in the willow shoots were significantly enhanced in the presence of EDTA alone and with ethyl lactate, except for the PHE concentration in stems with EDTA alone. Under the same treatment, the presence of Cd had no significant influence on the PHE removal from soils. The results indicate the feasibility of using this willow together with both EDTA and ethyl lactate for the simultaneous removal of PHE and Cd from soils.

Oxygen vacancy diffusion in bare ZnO nanowires

Oxygen vacancies (VO) are known to be common native defects in zinc oxide (ZnO) and to play important roles in many applications. Based on density functional theory, we present a study for the migration of oxygen vacancies in ultra-thin ZnO nanowires (NWs). We find that under equilibrium growth conditions VO has a higher formation energy (Ef) inside the wire than that at shallow sites and surface sites, with different geometric relaxations and structural reconstructions. The migration of VO has lower barriers in the NW than in the bulk and is found to be energetically favorable in the direction from the bulk to the surface. These results imply a higher concentration of VO at surface sites and also a relative ease of diffusion in the NW structure. Our results support the previous experimental observations and are important for the development of ZnO-based devices in photocatalysis and optoelectronics.

Risk prognosis factors of chronic subdural hematoma evacuated by the novel YL-1 hollow needle aspiration drainage system

AIM

The novel YL-1 hollow needle aspiration drainage system is an effective minimally invasive treatment in chronic subdural hematoma (CSDH). In order to find the risk prognosis factors of chronic subdural hematoma (CSDH) performed by the novel YL-1 hollow needle aspiration drainage system, a logistic analysis of postoperative results was performed.

METHODS

One hundred ninety-four cases of chronic subdural hematoma in a period of 7 years since 2004 were collected. According to the postoperative rehabilitation effect of nerve function, the patients were divided into good prognosis group and poor prognosis group. The patients' indexes of the two groups with age, blood coagulation function, location of the hematoma, hematoma volume, admission Markwalder's grade, clinical symptoms were tested by the chi-square test, then the statistically significant factors were selected into the establishment of the Logistic regression model and further analysis of multiple factors were made on chronic subdural hematoma prognostic implications.

RESULTS

Retrospective analysis was performed for differentiating good prognosis group (N.=174) and poor prognosis group (N.=20). Univariate analysis after the chi-square test showed that there were significant differences in gender, age, coagulation function, hematoma position, hematoma size, initial Markwalder's neurological grade, clinical symptoms and signs. Logistic regression analysis showed that chronic subdural hematoma prognostic factors sorted by odds ratio were as follows: high Markwalder's grade, male, coagulopathy, bilateral hematoma, senior citizens.

CONCLUSION

We used logistic regression analysis to identify the risk prognosis factors of chronic subdural hematoma (CSDH) performed by a novel YL-1 hollow needle aspiration drainage systems, and found that high preoperative Markwalder's gradie, male, coagulopathy, bilateral hematoma, senior citizens will poorly affect prognosis in CSDH.

Optimal electron doping of a C60 monolayer on Cu(111) via interface reconstruction

We demonstrate the charge state of C60 on a Cu(111) surface can be made optimal, i.e., forming C60(3-) as required for superconductivity in bulk alkali-doped C60, purely through interface reconstruction rather than with foreign dopants. We link the origin of the C60(3-) charge state to a reconstructed interface with ordered (4x4) 7-atom vacancy holes in the surface. In contrast, C60 adsorbed on unreconstructed Cu(111) receives a much smaller amount of electrons. Our results illustrate a definitive interface effect that affects the electronic properties of molecule-electrode contact.

[Protection of polysaccharide ATPS-2 from Armillariella tabescens on immunological liver injury in mice induced by BCG plus LPS]

OBJECTIVE

To observe the effect of polysaccharide ATPS-2 from Armillariella tabescens on the immunological liver injury in mice induced by BCG plus LPS.

METHOD

BCG and LPS were adopted to establish BCG plus LPS liver injury model in mice. The content of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and NO, the activity of superoxide dismutase (SOD) and malondiadehyde (MDA) content of liver homogenate in mice were measured by colorimetric method. The content of tumor necrosis factor-alpha (TNF-alpha), interleukin-1 (IL-1), on serum were measured by enzyme linked immunosorbent assay (ELISA) , and T- and B-lymphocyte proliferation were measured by MTT. Index of liver, spleen and thymus were calculated after treatment.

RESULT

Polysaccharide ATPS-2 from A. tabescens (25, 50, 100 mg x kg(-1)) could obviously reduce the high level of ALT, AST, NO and TNF-alpha, IL-1 on serum, inhibit the high level of MDA, increase the low activity of SOD in liver homogenate and enhance T-and B-lymphocyte proliferation, elevate the spleen, thymic index and decrease liver index of the mice to different extent.

CONCLUSION

Polysaccharide ATPS-2 from A. tabescens had apparently protective effects in the immunological liver injury mice induced by BCG plus LPS.

[Protection of polysaccharides-2b from mudan cortex of Paeonia suffruticosa andr on diabetic cataract in rats]

OBJECTIVE

To observe the the protective effection of polysaccharides-2b of mudan cortex of Paeonia suffruticosa andr (PSM2b) on diabetic cataract.

METHOD

The animal model of diabetic cataract in rats was induced by streptozotocin (STZ) and freund's adjuvant complete (CFA). The initial opacity occurrence time in lens was investigated with cranny lamp, and opacity degree of lens was compared too. The activities of glutathione peroxidase (GSH-pX), superoxide dismutase (SOD), catalase (CAT), the content of malonaldehyde (MDA) in serum and lens were detected. At the same time, the activities of Na(+) -K(+) -ATPase, the content of macromolecular weight protein and infusibility protein in lens were detected too.

RESULT

The results examinated by cranny lamp showed that PSM2b could significantly postpone the occurrence and alleviate opacity degree of lens. Compared with model group, every treatment group of PSM2b could lower the level of MDA, high and middle dose groups could increase the levels of SOD, GSH-pX, CAT in serum and lens in evidence, and enhance the activity of Na(+) -K(+) -ATPase. These indexes present favorable positive correlation between dose and effect.

CONCLUSION

All these results demonstrated that PSM2b had apparently protective effection on diabetic cataract in rats.

Ab Initio Electron Transport Study of Carbon and Boron−Nitrogen Nanowires

We report first-principles calculations on the electrical transport properties of two kinds of one-dimensional nanowires: (a) a carbon nanowire (CNW) with alternating single and triple bonds and (b) a boron-nitrogen nanowire (BNNW) with equidistant bonds. We demonstrate the similarity and difference between the carbon nanowire and its boron-nitrogen analogue in the molecular orbital and transport properties, and then explore the potential innovations. The effects of molecular orbitals and nanowire-electrode coupling on the transport properties are analyzed. The cases of the nanowires sandwiched between both nanoscale and bulk electrodes are considered. It suggests that the characteristics of the transmission spectra and the current-voltage characteristics (I-V curves) are determined both by the electrodes and by the molecule as well as their coupling. In particular, the negative differential resistance (NDR) phenomenon is more apparent when the nanowires are positioned between two nanoscale electrodes. The tuning of the transport properties is also probed through the changes of nanowire-electrode separation and the inclusion of a gate voltage. These lead to dramatic variations in the equilibrium conductance, which can be understood from the shift and alignment of the molecular orbital relative to the Fermi level of the electrodes. In the analysis of the effects of nanowire-electrode separation, it shows that the equilibrium conductance has the same variation behavior as that of the projected density of states (PDOS) for CNW, while the localized molecular orbitals of BNNW result in its conductance varies differently from its PDOS. The different molecular orbital characteristics near the Fermi level of these two kinds of nanowires underlie their different transport properties.

Detection of approximal caries in digital radiographs before and after correction for attenuation and visual response. An in vitro study

OBJECTIVE

To evaluate if digital compensation for exponential attenuation and the characteristics of the human visual system improves the diagnosis of approximal caries from digital radiographs.

MATERIAL AND METHODS

Forty premolar teeth were mounted in plaster blocks. Radiographs of the teeth were exposed with the Dixi digital intraoral system employing a Prostyle Intra dental X-ray unit (Planmeca Oy, Helsinki, Finland). Thirteen radiographs were then processed to compensate for the exponential attenuation and for the characteristic of the human visual system using equations presented in the paper. Ten observers were asked to diagnose approximal caries in all radiographs. ROC analyses were performed. The teeth were subsequently sectioned for histological validation of the lesions. The areas under ROC curves of original and processed radiographs were compared and analysed using Wilcoxon's signed-ranks test.

RESULTS

There were significant diagnostic differences between the two types of radiographs (all lesions P=0.005. enamel P=0.028, and dentine P=0.050).

CONCLUSION

Digital radiographs processed to compensate for exponential attenuation and the characteristics of the human visual system significantly improves the diagnosis of approximal caries in vitro.

The effect of hyaluronan on bone and soft tissue and immune response in wound healing

BACKGROUND

The aims of this study were to investigate the anti-inflammatory effect and the effect on bone regeneration of hyaluronan in surgical and non-surgical groups.

METHODS

In each of 15 individuals, 2 teeth with defects of similar character and magnitude in the upper or lower jaw were chosen. There were at least 2 teeth between the test and the control sites. In the surgical group, a bioabsorbable membrane was used for both test and control sites, and hyaluronan was placed in the intrabony pocket of the test site. In the non-surgical group, the periodontal pockets were scaled and hyaluronan was administered 3 times with an interval of 1 week in the test pockets. Alveolar bone height and bone healing patterns were analyzed using digital intraoral radiographs. Measurements of bone height were performed in the original digital black-and-white radiographs to obtain quantitative data on bone gain or loss. Bone healing patterns were studied with color-coded radiographs, using specially designed software in a personal computer with subsequent combinations of radiographs. Gingival crevicular fluid immunoglobulin (Ig)G, C3, and prostaglandin E2 (PGE2) responses; periodontal probing depth; bleeding on probing; and the presence of plaque were studied to evaluate the anti-inflammatory effect. Data were obtained at baseline before treatment, and at 2 weeks, and 1, 3, 6, and 12 months after treatment.

RESULTS

For the surgical treatments, bone height was increased in the test group treated with hyaluronan (mean value 2.2%, corresponding to an average increase of approximately 0.5 mm) and reduced in the control group (mean value -1.8%, corresponding to an average decrease of approximately - 0.4 mm) (P<0.05) after 12 months. For the non-surgical treatments, bone height was reduced by a mean value of -1.1% (corresponding to an average decrease of approximately -0.25 mm) in the test group treated with hyaluronan and -3.3% (corresponding to an average decrease of approximately -0.75 mm) in the control group after 12 months (N.S.). According to the digital color-coded radiographs, the test sites in the surgical and non-surgical groups showed apposition of bone minerals. Immune responses showed no differences during the 12 months studied for the surgical and non-surgical sites. Mean periodontal probing depths were reduced between 2.5 mm and 4.1 mm in the surgical and non-surgical groups.

CONCLUSIONS

The observed difference in bone height between test and control sites in the surgical group after 12 months was less than 1 mm, which was only detectable on radiographs. No statistical difference was found on radiographs in the non-surgical group, where a decrease in bone height was found for both groups after scaling. Probing depth reduction after the surgical treatment, as well as after scaling and root planing, was as expected. Hyaluronan in contact with bone and soft tissues had no influence on the immune system in this study. Further studies are needed to determine the extent to which hyaluronan can lead to clinically significant healing of periodontal lesions.

Conventional and predicted perceptibility curves for contrast-enhanced direct digital intraoral radiographs

OBJECTIVES

To construct Perceptibility Curves (PCs) for contrast-enhanced digital intraoral radiographs.

METHODS

Radiographs of a test object having holes of increasing depths were exposed using three digital systems, the CDR (Schick Technologies, Long Island, NY, USA), the Dixel (J Morita MFG, Kyoto, Japan) and the Sens-A-Ray (Regam Medical Systems, Sundsvall, Sweden). The radiographs were contrast-enhanced and PCs constructed in the conventional way using 10 observers. Predicted PCs were calculated and compared with observer data.

RESULTS

The PCs showed that contrast enhancement is effective for the perception of small contrast details, especially in the low exposure range. Predicted PCs demonstrated excellent agreement with observer data.

CONCLUSIONS

Contrast enhancement should be advantageous in digital radiography. The effects of contrast enhancement on PCs may be predicted without previous knowledge of observer performance.

Eruption pattern of autotransplanted premolars visualized by radiographic color-coding

Eruption patterns and root growth were visualized with the use of a new technique, radiographic color-coding, for comparison of the development of autotransplanted premolars with contralateral control teeth. Rates of eruption and root growth were studied. The eruption pattern and rate was assessed relative to the first molar. Maximum rates were found to occur between 30 and 60 days after transplantation. There were no significant differences between transplants and their contralaterals. Two distinct categories of eruption patterns were demonstrated. One group showed a tendency toward an initial rate of transplant eruption that was somewhat faster than that of the contralaterals. The other group showed initially retarded eruption. Possible explanations were discussed. Because no significant differences between the transplants and the contralaterals were observed, it was concluded that autotransplantation is a sound treatment option for substitution of missing teeth, at least from a tooth development point of view.

Validation of DIAGNOdent for quantification of smooth-surface caries: an in vitro study

The aims were 1) to validate a laser-based device, KaVo DIAGNOdent, for quantification of caries lesions on smooth surfaces, using histopathologic and microradiographic analyses as the gold standard, and 2) to test inter- and intra-observer agreements. We also investigated the influence on DIAGNOdent readings of the storage medium used for extracted teeth. Two observers measured independently the tooth surfaces of 40 extracted premolars that had been stored in thymol-saturated saline. After subsequent storage in neutral-buffered formalin for 14 days they were re-measured. The teeth were then sectioned for histopathologic and microradiographic analysis. The Spearman rank correlation coefficients between lesion depth and DIAGNOdent readings were 0.78-0.83 and 0.85 for teeth stored in thymol-saturated saline and formalin, respectively. Inter- and intra-observer agreements were 0.94 and 0.95 when the teeth were stored in thymol-saturated saline. The DIAGNOdent reading was almost 1.5 times higher for teeth stored in formalin than for those stored in thymol saline. The Spearman rank correlation coefficient between mineral loss in enamel (deltaZ) and DIAGNOdent readings ranged from 0.64 to 0.68. It was concluded that DIAGNOdent may be helpful for assessing smooth-surface caries, but the cut-off points need to be assessed under clinical conditions. The increase in fluorescence associated with storage of teeth in formalin warrants further investigation.

Comparison of QLF and DIAGNOdent for quantification of smooth surface caries

The aim was to compare the detection and quantification of smooth surface caries by KaVo DIAGNOdent and quantitative laser/light-induced fluorescence (QLF) using a laser and a lamp as two different light sources. On 40 premolar teeth extracted from adolescents, 71 non-cavitated approximal surfaces were assessed. For QLF, both mean and maximum fluorescence losses were registered. To provide a gold standard for verification, the teeth were then sectioned and lesion depth, stratified on a five-point scale, was determined by histopathology and microradiography. The correlation between the gold standard and the two methods was assessed by Spearman's rank correlation coefficient. The sensitivity and specificity of the methods for detection of smooth surface caries at D(3) level were also assessed. For lesion depth, correlation with the gold standard was similar for QLF and DIAGNOdent: about 0.85. With respect to dentinal caries detection, sensitivity for DIAGNOdent was 0.75 and specificity 0.96, with a cut-off point of 9. The corresponding values for QLF were 0.94 and 1, with a cut-off value of 20% of fluorescence loss. Spearman's rank correlation coefficients for enamel mineral loss and QLF and DIAGNOdent, respectively, were 0.76 and 0.67. It was concluded that for quantification of smooth surface caries, the methods are of equal merit, but for scientific purposes, QLF offers the advantage of closer correlation with changes in mineral content.

Tuned-aperture computed tomography for detection of occlusal caries

OBJECTIVES

To evaluate the use of tuned-aperture computed tomography (TACT) for the detection of primary occlusal caries.

MATERIALS AND METHODS

The material comprised 76 extracted posterior teeth, 51 with caries. Radiographs were recorded both with the Sens-A-Ray (Regam Medical Systems Int. AB, Sundsvall, Sweden) digital radiographic system and with Kodak EktaSpeed Plus film (Eastman-Kodak Co., Rochester NY, USA) employing an Orthopantomograph OP 100 (Instrumentarium Imaging, Tuusula, Finland) and a Prostyle Intra (Planmeca, Helsinki, Finland) dental unit respectively. The Sens-A-Ray radiographs were used to construct TACT slices and TACT iterative slices. The teeth were subsequently sectioned in 300 microm thick slices. Microradiographs were exposed and analysed with respect to the true presence of lesions. Seven observers subjectively evaluated the radiographs and ROC analyses performed. Conventional radiographs were compared with TACT images by means of the area under the ROC curves, Az. Paired t-test was used to compare Az values. Interobserver agreement was evaluated using the Kendall coefficient and the Friedman Anova.

RESULTS

TACT radiographs were significantly better than conventional radiographs for diagnosing all types of occlusal caries combined (P(TACT) (slices)=0.02. P(TACT) (iterative slices)=0.01). However, neither TACT system was significantly better than film for enamel and dentinal caries separately. Observer agreement was moderate. However, observers demonstrated significant systematic differences in their readings (P<0.001).

CONCLUSION

TACT may be a feasible method for diagnosing primary occlusal caries.

Prevalence of antibodies to Toxoplasma gondii in the sera of rare wildlife in the Shanghai Zoological Garden, People's Republic of China

The prevalence of antibodies to Toxoplasma gondii in the sera of rare wildlife in the Shanghai Zoological Garden, PR China, was examined using a modified agglutination test (MAT) and an enzyme-linked immunosorbent assay (ELISA). Forty-one (35%) of 117 animals belonging to two classes, 10 orders, 18 families, 37 genera and 52 species (including sub-species) were sero-positive for MAT. By MAT, T. gondii antibodies were found in 11.1% (4/36) of birds, in 25% (4/16) of primates, in 69.4% (25/36) of carnivores and in 27.6% (8/29) of herbivores. Thirty-three (33.7%) of 98 animals tested by protein A ELISA were sero-positive. By ELISA, T. gondii antibodies were found in none of 36 birds, in 33.3% (4/12) of primates, in 87.1% (27/31) of carnivores and in 10.5% (2/19) of herbivores.

Occlusal caries detection with KaVo DIAGNOdent and radiography: an in vitro comparison

A new laser fluorescence method, KaVo DIAGNOdent, was tested with respect to reproducibility and validity and compared with radiography regarding accuracy in the detection of occlusal caries. Seventy-six extracted premolar and molar teeth were measured twice with DIAGNOdent under both wet and dry conditions, at an interval of 2 weeks. Conventional film radiographs were exposed. Microradiographic analysis of sections of the teeth served as the gold standard. Intra-class correlation coefficient and Pearson's correlation coefficient were used to assess the reproducibility and the validity of the method, respectively. The influence of time and varying humidities on DIAGNOdent readings were analysed by two-way repeated measure ANOVA. ROC curves were plotted for DIAGNOdent readings and radiographic registration of caries by 6 observers, and the areas under the curves were compared using Student's t test. Under both wet and dry conditions, the reproducibility of the DIAGNOdent method was excellent: R = 0.97 and 0.96, respectively. The diagnostic accuracy of DIAGNOdent was significantly better than that of radiography (p< or =0.001). In this in vitro study of detection of occlusal caries, the diagnostic performance of the DIAGNOdent method was superior to that of radiography.

Physical evaluation of a system for direct digital intra-oral radiography based on a charge-coupled device

OBJECTIVES

To determine technical properties of a direct digital intra-oral radiographic system, the Dixel(R) (J Morita Corporation, Kyoto, Japan).

METHODS

A dose response function and the dark current were calculated from two series of exposures to a homogeneous radiation field. The line spread function (LSF) and the modulation transfer function (MTF) were determined from radiographs of an edge. The noise power spectrum (NPS) was determined at three exposures from radiographs exposed to homogeneous radiation fields. Noise equivalent quanta (NEQ) were calculated from the one-dimensional NPS and the MTF. The detective quantum efficiency (DQE) was determined from the NEQ and a representative value of the photon fluence. Signal-to-noise ratios (SNR) were calculated from the NEQs and different signal contrasts.

RESULTS

The dose response function demonstrated a slight curvature. There was no effect of the dark current. NPS ranged from 10-5 - 10-7 mm2 depending on exposure and frequency. At a peak of about 2 cycles/mm the DQE is on an average about 30 per cent. SNRs are favorable.

CONCLUSION

The technical properties found in this study indicate that the Dixel(R) system is suitable for intra-oral dental radiography.

Prediction of perceptibility curves of direct digital intraoral radiographic systems

OBJECTIVES

To derive and test a method to predict Perceptibility Curves (PCs) for direct digital intraoral radiographic systems.

METHODS

A test object was used to determine the performance of an average observer with respect to the threshold contrast and internal noise of the human visual system. These data were combined with system parameters to predict PCs mathematically.

RESULTS

Data on the performance of an average observer could be defined to obtain values of the effective threshold contrast as a function of background gray level. This function combined with the gamma-value of the system predicted PCs that agreed well with PCs obtained in the conventional way.

CONCLUSION

It is possible to predict PCs from a limited number of system parameters together with predetermined data on an average observer.

Orthodontic application of color image addition to visualize differences between sequential radiographs

A new technique was developed making it possible to visualize changes that take place after premolar transplantation. Three sequential radiographs from a series of standardized control examinations were digitized and registered to the first radiograph in the series using subtraction technique. The digitized radiographs were then transformed into monochromatic images: red, blue, and green. After correction of gray level and contrast, the three radiographs were superimposed. All details that were common in the radiographs were then displayed in black-and-white. Details that were different appeared in color. Red and blue combines into magenta, blue and green into cyan, and green and red into yellow. A procedure was developed to create color-coded radiographs according to the above. The procedure was applied to cases that had been treated by premolar transplantation. The color coding offers the possibility to identify any radiographic changes that take place over time, eg, growth, apposition or resorption of bone, and progression or regression of pathological processes.

A simplified method to obtain perceptibility curves for direct dental digital radiography

OBJECTIVES

To derive and test a simplified method to construct Perceptibility Curves (PCs) for dental digital detectors.

METHODS

Mathematical expressions were derived to make it possible to construct PCs from viewer data obtained at two exposures, one low and one high. PCs were constructed applying these expressions and compared with data previously obtained employing the conventional method.

RESULTS

PCs constructed according to the simplified method agree extremely well with conventionally obtained data.

CONCLUSIONS

Reliable PCs may be constructed according to the simplified method.

Comparison of observer reliability in assessing alveolar bone changes from color-coded with subtraction radiographs

OBJECTIVES

To assess intra- and interobserver agreement on marginal changes in periodontal bone from color-coded compared with subtraction radiographs.

METHODS

Sequential radiographs from patients undergoing periodontal treatment were acquired using direct digital intra-oral radiography. Fifty-one pairs of color-coded and subtraction radiographs were produced and evaluated twice by six dentists for changes in marginal bone. Intra- and interobserver agreement were calculated.

RESULTS

Intra-observer agreement was significantly higher for the color-coded radiographs (P < 0.05). Interobserver agreement was significantly higher for color-coded radiographs at the second (P < 0.001) but not the first (P = 0.34) evaluation.

CONCLUSIONS

Color coding of radiographic differences by means of image addition may be a feasible alternative to the subtraction technique for evaluating periodontal bone changes.

The perceptibility curve test applied to direct digital dental radiography

OBJECTIVE

To compare the effect of an additional scintillator layer on the psychophysical properties of a CCD detector for digital dental radiography.

METHODS

Radiographs of a test object containing ten holes of increasing depth were obtained throughout the exposure range of two CCD detectors at 70 and 90 kVp. One was the original detector for the Sens-A-Ray system (Regam Medical Systems, Sundsvall, Sweden) and the other the same detector covered by a scintillator layer. Ten viewers evaluated the radiographs for the number of perceptible holes. From these data and the dose response functions for the two detectors, the minimum perceptible exposure difference was found. The reciprocal values of this parameter were plotted against the logarithm of exposure to create Perceptibility Curves (PCs).

RESULTS

The four PCs had essentially the same shape and height. There was a shift to lower exposures in the PCs for the detector covered by a scintillator.

CONCLUSIONS

The two detectors have essentially the same psychophysical properties. Since the detector covered by a scintillator layer is more sensitive, it should be preferred for clinical practice since the dose to the patient is reduced.

A sensitometric comparison of four dental X-ray films and their diagnostic accuracy

OBJECTIVES

To compare the sensitometric properties and accuracy in the diagnosis of approximal caries of two E-speed (Ektaspeed Plus and EV 57) and two D-speed (Ultra-speed and DV 57) films.

METHODS

Speed and contrast for the four films were determined following 30 exposures for each film. Base plus fog density was measured on unexposed films and the increase was studied over a 18-month period. Seventy-five extracted premolars with known pathology were radiographed under standardized conditions and the radiographs assessed by nine observers for approximal caries. Receiver Operating Characteristic (ROC) curve technique was used to analyse the diagnostic accuracy.

RESULTS

The sensitometric analysis showed that the Ektaspeed Plus film had the highest speed of the four films. At a density of 1.0 it was 2.28 times faster than Ultra-speed. The contrast of Ektaspeed Plus was comparable with that of the other films and base plus fog density plateaued at 0.4 ten months before expiry date. There were no statistically significant differences in diagnostic accuracy for white spot lesions between the four films. For cavitations there was a significant difference between EV 57 and DV 57 and Ektaspeed Plus (P = 0.005) but not between Ultra-speed and Ektaspeed Plus nor between Ultra-speed and EV 57 and DV 57.

CONCLUSION

Ektaspeed Plus film is comparable with D-speed and a conventional E-speed film. Since it is at present the fastest available dental film it should be recommended for general dental practice.

Expression of the BE-20 epididymal protein gene: in situ hybridization

A protein designated as BE-20 was purified from cauda epididymal fluid of male rabbits and the amino acid sequence of the N-terminus was determined. A 23-mer oligonucleotide coding the N-terminal eight amino acids of the BE-20 protein was synthesized. The oligonucleotide was used as sense primer with rabbit epididymal mRNA as template in the RT-PCR system. The BE-20 cDNA consisted of 499 bp with an open reading frame of 285 bp encoding a deduced polypeptide composed of 95 amino acids. Digoxigenin-labeled BE-20 cDNA was prepared and used as a hybridization probe to detect the specific mRNA. The probe interacted with a 1.2-kb mRNA prepared from rabbit epididymis; mRNAs prepared from rabbit testis gave negative reaction. Using tissue sections, the BE-20 mRNA was located in the epithelial cells of the cauda epididymis and proximal segment of the ductus deferens by in situ hybridization method. Sections of the corpus and caput epididymis, testis, and liver gave negative reaction. Polyclonal anti-BE-20 antibodies were raised and found to inhibit in vitro the capacity of human sperm to penetrate zona-free hamster ova. The results suggest that BE-20 protein may influence maturation of spermatozoa during its movement through the epididymis and/or the capacity of sperm to fertilize ova.

Identification of a rabbit epididymal protein gene

A protein designated as BE-20 was purified from cauda epididymal fluid of the rabbit by preparative polyacrylamide gel electrophoresis and HPLC on a mono Q HR5/5 anion exchange column. The purified protein migrated with an estimated Mt of 20,000 when analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The amino acid sequence of the N-terminus of the BE-20 protein was determined. The initial eight amino acid residues were His-Gly-Ala-Asp-Lys-Pro-Gly-Val. The corresponding 23 mer oligonucleotide (5'-CATGGCGCTGACAAGCCTGGGGT-3') was synthesized and used as sense primer with rabbit epididymal mRNA as template in the RT-PCR system. The purified BE-20 cDNA consisted of 499 bp with an open reading frame of 285 bp encoding a deduced polypeptide composed of 95 amino acids. The BE-20 cDNA had 78.5% identity in 479 bp overlap with human epididymis-specific HE4 cDNA. The amino acid sequences of the initial 30 amino acid residues of the N-terminus of the purified protein and the deduced polypeptides were as follows: N-His-Gly-Ala-Asp-Lys-Pro-Gly-Val-Cys-Pro-Gln-Leu-Ser-Ala-Asp-Leu-Asn-Cy s- Thr-Gln-Asp-Cys-Arg-Ala-Asp-Gln-Asp-Cys-Ala-Glu. The deduced polypeptide contained 16 cysteine residues and had partial sequence homology with proteins belonging to the four-disulfide core family of extracellular proteinase inhibitors. The BE-20 protein may play a role in sperm maturation and/or capacitation.

Effect of extract of Hirudo Medicinalis L. against adherence of calcium oxalate crystals to acid-injured bladder mucosa

The effect of extract of Hirudo Medicinalis L. on preventing the adhesion of calcium oxalate crystals to 0.1 M hydrochloric acid-injured bladder urothelium of the rat was studied. It was found that in this species the extract coated to the bladder mucosa after it was instilled into the chemically injured bladder; and the adhesion of calcium oxalate crystals was prevented. In regard to the anti-adhesion property the Hirudo extract appears more effective than heparin, a documented glycosaminoglycan.

Antifertility effect of polyvinylpyrrolidone-gossypol and gossypol in male rats

Thirty-nine adult male Wistar rats were administered 20 mg/kg or 24.3 mg/kg polyvinylpyrrolidone-gossypol (PVP-G) and 20 mg/kg gossypol acetic acid (G-A) 6 times a week for 6 weeks. Mating test was taken to evaluate the antifertility effect. Caudal sperm count, body weight, sex and accessory sex organ weights were recorded. At the end of 6 weeks treatment, the recovery period of 6 weeks was investigated. The results showed that the onset of antifertility action and recovery with PVP-G are faster than with G-A.