Target mediated bioreaction to engineer surface vacancy effect on Bi2O2S nanosheets for photoelectrochemical detection of FEN1

Photoelectrochemistry represents a promising technique for bioanalysis, though its application for the detection of Flap endonuclease 1 (FEN1) has not been tapped. Herein, this work reports the exploration of creating oxygen vacancies (Ov) in situ onto the surface of Bi2O2S nanosheets via the attachment of dopamine (DA), which underlies a new anodic PEC sensing strategy for FEN1 detection in label-free, immobilization-free and high-throughput modes. In connection to the target-mediated rolling circle amplification (RCA) reaction for modulating the release of the DA aptamer to capture DA, the detection system showed good performance toward FEN1 analysis with a linear detection range of 0.001-10 U/mL and a detection limit of 1.4 × 10-4 U/mL (S/N = 3). This work features the bioreaction engineered surface vacancy effect of Bi2O2S nanosheets as a PEC sensing strategy, which allows a simple, easy to perform, sensitive and selective method for the detection of FEN1. This sensing strategy might have wide applications in versatile bioasssays, considering the diversity of a variety of biological reactions may produce the DA aptamer.

[circDDX17 targets miR-223-3p / RIP3 to regulate the proliferation and apoptosis of non-small cell lung cancer cells]

Objective: To explore the molecular mechanism of circDDX17 regulating the proliferation and apoptosis of non-small cell lung cancer cells by targeting the miR-223-3p/RIP3 molecular axis. Methods: The expression levels of circDDX17, miR-223-3p, and RIP3 in human normal lung epithelial cell lines BEAS-2B and non-small cell lung cancer cells H1299, A549, and H446 were detected by reverse transcription-quantitative real-time polymerase chain reaction (RT-qPCR). The plasmids of pcDNA, pcDNA-circDDX17, anti-miR-con, anti-miR-223-3p, pcDNA-circDDX17 and miR-con, pcDNA-circDDX17 and miR-223-3p mimics were transfected into H1299 cells. 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H tetrazolium bromide (MTT) assay was used to detect the cell proliferation. Flow cytometry was used to detect the cell cycle and cell apoptosis. Plate cloning experiment was used to detect cell proliferation ability. The dual luciferase report experiment was applied to verify the targeting relationship between miR-223-3p with circDDX17 and RIP3. Western blot was used to detect the protein expression of cyclinD1, CDK2, cleaved caspase-3 and Bax. Results: The expression levels of circDDX17 and RIP3 mRNA in H1299, A549, and H446 cells were significantly reduced (P<0.05), the expression level of miR-223-3p mRNA was significantly increased (P<0.05) compared with BEAS-2B. The cell viability [(69.46±4.68)%], the number of cell clones (83.49±7.86), the proportion of cells in S phase [(22.52±1.41) %], the protein expression levels of cyclinD1 and CDK2 in PCDNa-CircDDX17 group were lower than those in pcDNA group [(97.54±7.72)%, 205.03±13.37, (28.69±1.49)%, respectively, P<0.05], while the percentage of G0/G1 phase cells [(64.45±3.56)%], apoptosis rate [(18.36±1.63)%], the protein expression levels of cleaved caspase-3 and Bax in pcDNA-circDDX17 group were higher than those of pcDNA group [(51.33±2.76) % and (5.21±0.54) %, respectively, P<0.05]. The viability [(72.64±5.44)%], the number of cell clones (78.16±8.23), the proportion of S-stage cells [(21.34±1.59) %], the protein expression levels of CyclinD1 and CDK2 in anti-miR-223-3p group were lower than those in anti-miR-con group [(103.47±6.25)%, 169.32±14.53, (28.43±1.26)%, respectively, P<0.05]. Percentage of G0/G1 phase cells [(62.86±3.28)%], apoptosis rate [(14.64±1.67)%], the protein expression levels of cleaved caspase-3 and Bax in the anti-miR-223-3p group were higher than those of anti-miR-con group [(51.33±2.71)% and (4.83±0.39)%, respectively, P<0.05]. MiR-223-3p has complementary sites with circDDX17 or RIP3. The viability [(135.45±9.28)%], the number of cell clones (174.64±10.68), the proportion of S-phase cells [(26.39±2.25)%], the protein expression levels of cyclinD1 and CDK2 in pcDNA-circDDX17+miR-223-3p group were higher than those in pcDNA-circDDX17+miR-con group [(101.56±6.68)%, 107.65±7.62, (21.64±1.72)%, P<0.05]. Percentage of G0/G1 phase cells [(56.64±2.76)%], apoptosis rate [(8.34±0.76)%], the protein expression levels of cleaved caspase-3 and Bax in pcDNA-circDDX17+miR-223-3p group were lower than those of pcDNA-circDDX17+miR-con group [(64.03±3.48)% and (15.21±1.18)%, respectively, P<0.05]. Conclusion: circDDX17 could inhibit the proliferation and induce apoptosis of non-small cell lung cancer cells via targeting the miR-223-3p / RIP3 molecular axis.

The Relationship between Quantitative Parameters of Dual-energy CT and HIF-1α Expression in Non-Small Cell Lung Cancer

OBJECTIVE

This study aimed to investigate whether there is a correlation between quantitative parameters of dual-energy computed tomography (DECT) and the relative expression of HIF-1α in patients with non-small cell lung cancer (NSCLC) to preliminarily explore the value of DECT in evaluating the hypoxia of tumor microenvironment and tumor biological behavior and provide more information for the treatment of NSCLC.

METHODS

This retrospective research included 36 patients with pathologically confirmed NSCLC who underwent dual-energy enhanced CT scans. The quantitative parameters of DECT were analyzed, including iodine concentration, water concentration, the CT values corresponding to 40keV, 70keV, 100keV, and 130keV in arterial and venous phases, and the normalized iodine concentration and the slope of the energy spectrum curve were calculated. Postoperative specimens underwent HIF immunohistochemical staining by two pathologists. Spearman correlation analysis was adopted as the statistical methodology. The data were analyzed by SPSS26.0 statistical software.

RESULTS

Water concentration (r=0.659, P<0.001 and r= 0.632, P<0.001, the CT values corresponding to 100keV (r=0.645, P<0.001 and r= 0.566, P<0.001) and 130keV (r=0.687, P<0.001 and r= 0.682, P<0.001) in arterial and venous phases, and CT value of 70keV in arterial phase (r=0.457, P=0.005) were positively correlated with HIF-1α expression level. There was no correlation among iodine concentration, standardized iodine concentration, CT value of 40keV, λHU, and HIF-1α expression in arterial and venous levels (P >0.05).

CONCLUSION

The quantitative parameters of DECT have a certain correlation with HIF-1α expression in NSCLC. Moreover, it has been demonstrated that DECT can be used to predict hypoxia in tumor tissues and the prognosis of lung cancer patients.

Thioredoxin Reductase-Mediated Reaction Evokes In Situ Surface Polarization Effect on BiOIO3: Toward a New Sensing Strategy for Cathodic Photoelectrochemistry

We have witnessed the fast progress of cathodic photoelectrochemistry over the past decades, though its signal transduction tactic still lacks diversity. Exploring new sensing strategies for cathodic photoelectrochemistry is extremely demanding yet hugely challenging. This article puts forward a unique idea to incorporate an enzymatic reaction-invoked surface polarization effect (SPE) on the surface of BiOIO3 to implement an innovative cathodic photoelectrochemical (PEC) bioanalysis. Specifically, the thioredoxin reductase (TrxR)-mediated reaction produced the polar glutathione (GSH), which spontaneously coordinated to the surface of BiOIO3 and induced SPE by forming a polarized electric field, resulting in improved electron (e-) and hole (h+) pair separation efficiency and an enhanced photocurrent output. Correlating this phenomenon with the detection of TrxR exhibited a high performance in terms of sensitivity and selectivity, achieving a linear range of 0.007-0.5 μM and a low detection limit of 2.0 nM (S/N = 3). This study brings refreshing inspiration for the cathodic PEC signal transduction tactic through enzyme-mediated in situ reaction to introduce SPE, which enriches the diversity of available signaling molecules. Moreover, this study unveils the potential of in situ generated SPE for extended and futuristic applications.

[The efficacy of thin struct bare stents for the treatment of spontaneous isolated dissection of the superior mesenteric artery]

Objective: To examine the safety and effectiveness of thin struct bare stents for the treatment of spontaneous isolated dissection of the superior mesenteric artery (SIDSMA). Methods: The data of 32 patients admitted to First Hospital of Jiaxing (20 cases) and Jinling Hospital (12 cases) with SIDSMA from January 2016 to January 2021 were retrospectively analyzed. There were 27 males and 5 females, aging (54.8±9.4) years (range: 36 to 75 years). All patients were treated with thin struct bare stents. Controllable spring coils were used to fulfill the false lumen in 2 cases. Symptoms, vascular remodeling pattern at the SIDSMA lesion, and patency of the stents were observed during follow-up. Results: The surgical success rate was 100%. According to the length of the lesions and stents, the number of stents implanted was 1 in 17 cases, 2 in 11 cases and 3 in 4 cases. The angiography showed that blood flow in the stent was smooth and that the false lumen disappeared or weakened. The numerical rating scale for abdominal pain decreased from 6.1±1.5 (range: 4 to 10) preoperatively to 1.0 (1.0) (range: 0 to 3) 1 hour postoperatively (W=528, P<0.01). The compression rate of the true lumen of the superior mesenteric artery decreased from (92.3±6.7)% (range: 25% to 94%) preoperatively to 0.8 (1.2)% (range: 0 to 3.2%) 1 month postoperatively (W=528, P<0.01). The primary patency rate of CT angiography at 1 month postoperatively was 100%. The vascular remodeling rate was (92.3±6.7)% (range: 80% to 100%). All patients were followed for (46.3±17.0) months (range: 24 to 76 months). The cumulative patency rates in 1, 2 and 5 years were all 100%. Conclusion: The use of thin struct bare stents for SIDSMA is safety and efficacy.

[Incidence and risk factors of congenital ventricular septal defect in Qingdao]

Objective: To analyze the incidence and risk factors of ventricular septal defect (VSD) in Qingdao. Methods: A prospective cohort study design was used to include pregnant women who underwent prenatal screening in Qingdao between August 2018 and June 2020 (the whole population coverage). VSD was diagnosed according to the pulse oxygen saturation and heart auscultation, and the final diagnosis was made according to the echocardiography of VSD positive newborns within postnatal day 7. Results: The study included 115 238 live births, among which 388 were diagnosed as VSD, with an incidence of 3.37‰. The results of multivariate logistic regression analysis showed that mother with postgraduate level (OR=1.61, 95%CI: 1.00-2.58, P=0.049) (compared with junior high school and below), preterm birth history (OR=2.90, 95%CI: 1.47-5.70, P=0.002), and pregnancy history of congenital heart disease (OR=5.98, 95%CI: 2.63-14.73, P<0.001) were risk factors for VSD. Compared with female infants, the overall risk of VSD in male infants was relatively low (OR=0.74, 95%CI: 0.60-0.91, P=0.005). Conclusions: The incidence of VSD in Qingdao is 3.37‰. The risk factors of VSD include higher maternal education level, pregnancy history of congenital heart disease and preterm birth history. Moreover, the overall risk of VSD in male infants is low.

Catechol exerts an in situ surface oxygen vacancy effect on BiOI: an innovative signal transduction mode for cathodic photoelectrochemistry

Cathodic photoelectrochemistry, a research hotspot in state-of-art bioassays, is generally circumscribed by its monotonous signal transduction tactic of photoinduced electron transfer (PET) mechanism, which significantly narrows the scope of its applications. In this study, we reveal the surface oxygen vacancy (V_O) formation elicited by the spontaneous coordination of catechol (CA) onto the surface of BiOI nanoplates for the innovative operation of the cathodic PEC signal transduction tactic. The in situ-generated V_O functions as a carrier separation center to efficiently promote photocurrent generation. Taking tyrosinase (TYR) and Escherichia coli O157:H7 (E. coli O157:H7) as model targets, the established signal transduction tactic was validated as efficient and sensitive for the detection of the two targets with linear ranges from 1.0 × 10^-4 to 1.0 U mL^-1 and 5.0 to 1.0 × 10⁶ CFU mL^-1, respectively. Low-detection limits of 1.0 × 10^-4 U mL^-1 and 3.0 CFU mL^-1 were achieved for TYR and E. coli O157:H7, respectively. This study opens up a new perspective of in situ generated surface V_O on semiconductors, which underlies an innovative PEC signal transduction mechanism with convincing analytical performance. Hopefully, it might encourage more explorations of new methodologies for introducing surface vacancies with exquisite applications.

Kanamycin triggered nanozyme for homogeneous and amplified colorimetric detection of T4 polynucleotide kinase

It is of significance to develop efficient methods for detecting the activity of T4 polynucleotide kinase (T4 PNK) due to its essential role in the modulation of different life activities. In this work, we constructed a novel nanozyme using Kanamycin (KANA) as a trigger for the [Fe(CN)₆]^3- coordinated Cu₂(OH)₃NO₃ (Cu₂(OH)₃NO₃/[Fe(CN)₆]^3-) nanorods, and designed an amplified colorimetric method to detect T4 PNK. That was, the free KANA efficiently triggered the peroxidase-like activity of Cu₂(OH)₃NO₃/[Fe(CN)₆]^3-, while the bound KANA by its aptamer lost the stimulative capability for the nanomaterials. On the basis of the bioreaction regulated generation of the KANA aptamer, a highly sensitive colorimetric assay aided by the rolling circle amplification (RCA) reaction for the detection of T4 PNK was realized. Results showed that this assay can detect T4 PNK from 1.0 × 10^-3 to 10.0 U/mL, with a limit of detection (LOD) of 1.42 × 10^-4 U/mL. The assay also showed acceptable performance in the detection of T4 PNK in serum samples. In addition to the satisfactory sensitivity and selectivity, the displayed T4 PNK assay also presented merits of operational convenience, without labeling or immobilization process and did not require costly instrument. It is expected that the KANA as a stimulator would have extended biosensing applications by coupling various bioreactions that can produce the KANA aptamer.

In situ formed and switchable enzymatic activity of BiOBr under light stimulation for homogeneous and label-free bioassay

A new concept to construct photoresponsive nanozyme through the in situ deposition of electron transporting material (ETM) on BiOBr nanoplates was proposed. That was, the spontaneous coordination of ferricyanide ions (i.e., [Fe(CN)₆]^3-) onto the surface of BiOBr formed electron transporting material (ETM), which efficiently prevented electron-hole recombination and led to efficient enzyme mimicking activity under light stimuli. Moreover, the formation of the photoresponsive nanozyme was regulated by pyrophosphate ions (PPi) due to the competitive coordination of PPi with [Fe(CN)₆]^3- onto the surface of BiOBr. This phenomenon allowed the construction of an engineerable photoresponsive nanozyme that was coupled with the rolling circle amplification (RCA) reaction to elucidate a novel bioassay for chloramphenicol (CAP, taken as a model analyte). The developed bioassay manifested the merits of label-free, immobilization-free and with efficiently amplified signal. Quantitative analysis of CAP in a wide linear range from 0.05 to 100 nM with the detection limit of 0.015 nM was realized, which endowed the methodology with sufficiently high sensitivity. It is expected to be a powerful signal probe in bioanalytical field by virtue of its switchable and fascinating visible-light-induced enzyme mimicking activity.

Sensitive colorimetric assay of T4 DNA ligase by the oxidase nanozyme of LaMnO3.26 coupled with a hyperbranched amplification reaction

The development of efficient methods for the detection of T4 DNA ligase is extremely important for public health. The present work demonstrates the integration of engineerable oxidase nanozyme of LaMnO_3.26 nanomaterials for the colorimetric detection of T4 DNA ligase. Specifically, the LaMnO_3.26 nanomaterials exhibited oxidase-like activity, oxidizing o-phenylenediamine (OPD), 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), and 3,3',5,5'-tetramethylbenzidine (TMB) to their corresponding oxidation products, which featured maximum absorption wavelengths at 450, 417 and 650 nm, respectively, while pyrophosphate ion (PPi) caused an obvious decrease in the oxidase-like activity of LaMnO_3.26 through its surface coordination with the surface-exposed Mn element and induced aggregation of the nanozyme. Attributed to the PPi regulated oxidase nanozyme activity, LaMnO_3.26 served as a colorimetric probe for the quantitative detection of T4 DNA ligase assisted by a hyperbranched amplification reaction for signal amplification. The T4 DNA ligase was detected with a linear range of 4.8 × 10^-3 to 6.0 U mL^-1, achieving a detection limit of 1.6 × 10^-3 U mL^-1. The outcome indicated that the developed nanozyme might be extended to a broad range of practical applications.

Trap remediation of CuBi2O4 nanopolyhedra via surface self-coordination by H2O2: an innovative signaling mode for cathodic photoelectrochemical bioassay

This work conveys a new philosophy of surface self-coordination mediated trap remediation for innovative cathodic photoelectrochemical (PEC) signal transduction. Initially, the surface trap states of CuBi₂O₄ nanopolyhedra resulting from dangling bonds can function as charge carrier recombination centers, which suppress the carrier separation efficiency and result in a low photocurrent output. Particularly, hydrogen peroxide (H₂O₂) spontaneously interacts with the uncoordinated Cu(II) on the surface of CuBi₂O₄, enabling efficient elimination of dangling bonds and remedy of trap states, thereby outputting intensified photocurrent readout. Exemplified by Flap endonuclease 1 (FEN1) as a model target, a tetrahedron DNA (THD)-based strand displacement amplification (SDA) was introduced to manipulate the formation of hemin impregnated G-quadruplex (G-quadruplex/hemin) DNAzyme and the resultant catalytic reduction for H₂O₂. In addition, a highly efficient and ultra-sensitive PEC sensing platform was achieved for FEN1 detection with a wide linear range from 1.0 fM to 100.0 pM and a detection limit of 0.3 fM (S/N = 3). This work not only establishes a new idea of cathodic PEC signal transduction, but also offers an efficient biosensing platform for FEN1.

Highly selective photocatalytic oxidation of 5-hydroxymethylfurfural by interfacial Pt-O bonding Pt-Ov-BiOBr

The 5-hydroxymethylfurfural (HMF) photocatalytic oxidation has the advantages of mild conditions and controllable oxidation degree. There are a number of ways to increase its reactivity by boosting the production of...

Self-coordinated nanozyme on Cu3BiS3 nanorods for high-performance aptasensing

A novel strategy is reported to access high-performance nanozymes via the self-coordination of ferrocyanides ([Fe(CN)₆]^4-) onto the surface of the Cu₃BiS₃ (CBS) nanorods. Notably, the in situ formed nanozymes had high catalytic activity, good stability, low cost, and easy mass production. The formed nanozyme catalyzed the oxidation of the typical chromogenic substrate of 3,3',5,5'-tetramethylbenzidine (TMB) with a distinctive absorption peak at 652 nm, accompanied by a blue color development. Moreover, the attachment of deoxyribonucleoside 5'-monophosphates (dNMP) beforehand onto the surface of CBS prevented coordination of ferrocyanides and resulted in the tunable formation of the nanozyme, thereby enabling the construction of an exquisite biosensing platform. Taking the aptasensing of chloramphenicol (CAP) as an example, the engineered nanozyme allowed the construction of a homogenous, label-free, and high-performance bioassay in terms of its convenience and high sensitivity. Under the optimal conditions, changes in the absorption intensity at 652 nm for the oxidized TMB provides a good linear correlation with the logarithm of CAP concentrations in the range 0.1 pM to 100 nM, and the limit of detection was 0.033 pM (calculated from 3σ/s). Considering a vast number of bioreactions can be connected to dNMP production, we expect the engineerable nanozyme as a universal signal transduction scaffold for versatile applications in bioassays. Through the attachment of deoxyribonucleoside 5'-monophosphate (dNMP) on the surface of CBS to regulate the generation of self-coordinated nanozyme CBS/BiHCF, a homogeneous, label-free, and high-performance universal aptasensing platform was constructed.

[Clinical features and risk factors for early relapse of pediatric ulcerative colitis]

Objective: To investigate the clinical features of pediatric ulcerative colitis (UC) and analyze the risk factors of disease relapse. Methods: The clinical data of 79 children with UC diagnosed in Beijing Children's Hospital, Capital Medical University from January 2016 to February 2021 were retrospectively analyzed. They were divided into early relapse group and non-early relapse group according to the clinical relapse within 12 months after diagnosis. T-test, rank sum test, χ² test or Fisher's exact test were used to compare the variables between the 2 groups, including the clinical features, laboratory examination results and treatments. The Logistic regression was used to analyze the risk factors of early relapse. The cumulative relapse rate during follow-up was calculated by Kaplan-Meier method. Results: Among the 79 UC children, 46 were males and 33 were females, and the age of onset was 10.6 (6.4, 12.7) years. The children were mainly characterized by extensive disease (E3) and pancolitis (E4) (51/79, 65%), moderate to severe activity (48/79, 61%) and moderate to severe inflammation of colonic mucosa (71/79, 90%). Thirty-eight (48%) patients had atypical phenotype and 17 (22%) had extraintestinal manifestations. The follow-up period was 43.9 (22.8, 61.3) months, and of the 41 patients rechecked with colonoscopy, 7 (17%) had disease progression. According to Kaplan-Meier analysis, the cumulative relapse rate of the 79 cases at 3 months, 6 months, 1 year and 2 years after diagnosis were 27% (21/79), 47% (37/79), 57% (45/79) and 73% (53/73), respectively. There were 45 children (57%) in early relapse group and 34 (43%) in non-early relapse group. In early relapse group, hemoglobin and mucosal healing rate were both significantly lower (105 (87, 122) vs. 120 (104, 131) g/L, 28% (7/25) vs. 7/9, Z=-2.38, χ²=4.87, both P<0.05). The rate of steroid-dependent, E3 and step-up therapy during the induction period were all significantly higher than those in non-early relapse group (11/19 vs. 1/12, 24% (11/45) vs. 6% (2/34), 29% (13/45) vs. 6% (2/34), χ²=5.67, 4.85, 6.66, all P<0.05). Multivariate Logistic regression analysis showed that extraintestinal manifestations (OR=4.33, 95%CI 1.05-17.83), E3 (OR=8.27, 95%CI 1.47-46.46) and step-up therapy during the induction period (OR=5.58, 95%CI 1.01-30.77) were independent risk factors for early relapse. Conclusions: Pediatric UC is usually extensive and severe, with atypical phenotype, a high rate of relapse and a risk of disease progression. Extraintestinal manifestations, E3 and step-up therapy during the induction period are independent risk factors for early relapse.

Agriterribacter soli sp. nov., isolated from herbicide-contaminated soil

A Gram-stain-negative, non-spore-forming and rod-shaped bacterium, designated strain NS-102T, was isolated from herbicide-contaminated soil sampled in Nanjing, PR China, and its taxonomic status was investigated by a polyphasic approach. Cell growth of strain NS-102T occurred at 16–42 °C (optimum, 30 °C), at pH 5.0–8.0 (optimum, pH 6.0) and in the presence of 0–3.5 % (w/v) NaCl (optimum, without addition of NaCl). The 16S rRNA gene sequence of strain NS-102T shows high similarity to that of Agriterribacter humi YJ03T (96.9 % similarity), followed by Terrimonas terrae T16R-129T (93.8 %) and Terrimonas pekingensis QHT (93.6 %). Average nucleotide identity, average amino acid identity and digital DNA–DNA hybridization values between the draft genomes of strain NS-102T and A. humi YJ03T were 72.5, 69.4 and 18.6%, respectively. The only respiratory quinone was MK-7, and phosphatidylethanolamine and unidentified lipids were the major polar lipids. The major cellular fatty acids of strain NS-102T contained high amounts of iso-C15 : 0 (24.6 %), iso-C17 : 03-OH (24.1 %), iso-C15 : 0 G (16.6 %) and summed feature 3 (C16 : 1  ω6c and/or C16 : 1  ω7c) (15.6 %). The G+C content of the total DNA was determined to be 40.0 mol%. The morphological, physiological, chemotaxonomic and phylogenetic analyses clearly distinguished this strain from its closest phylogenetic neighbours. Thus, strain NS-102T represents a novel species of the genus Agriterribacter , for which the name Agriterribacter soli sp. nov. is proposed. The type strain is NS-102T (=CCTCC AB 2017249T=KCTC 62322T).

Graphite carbon rings modified carbon nitride with strong built-in electric field for high photocatalysis-self-Fenton performance

The photocatalysis-self-Fenton is a novel technology for high-fluent degradation and high mineralization of aqueous organic pollutants. Herein, we constructed a novel photocatalysis-self-Fenton system in which graphite carbon (Cg) rings-doped graphitic...

Nickel oxide@nickel-graphene quantum dot self-healing hydrogel for colorimetric detection and removal of lambda-cyhalothrin in kumquat

Detection and removal of pesticide residues in fruit and vegetable are important to ensure human health, but the current methods face challenges in sensitivity, specificity and convenience of use. The...

Surface polarization of BiOI to boost the photoelectrochemical signal transduction for high performance bioassays

The surface hydroxylation induced polarization (SHIP) is disclosed as an effective tactic to promote the cathodic photoelectrochemical (PEC) communication of bismuth oxyiodide with doxorubicin (Dox) by as large as three...

Invoking Cathodic Photoelectrochemistry through a Spontaneously Coordinated Electron Transporter: A Proof of Concept Toward Signal Transduction for Bioanalysis

Most of the cathodic photoelectrochemical (PEC) bioassays rely on electron accepting molecules for signal stimuli; unfortunately, the performances of which are still undesirable. New signal transduction strategies are still highly expected for the further development of cathodic photoelectrochemistry as a potentially competitive method. This work represents a new concept of invoked cathodic photoelectrochemistry by a spontaneously formed electron transporter for innovative operation of the sensing strategy. Specifically, the hexacyanoferrate(II) in solution easily self-coordinated with CuO nanomaterials and formed electron transporting copper hexacyanoferrate (CuHCF) on the surface, which endowed improved carrier separation for presenting augmented photocurrent readout. Exemplified by the T4 polynucleotide kinase (T4 PNK) and its inhibitors as targets, a homogenous cathodic PEC biosensing platform was achieved with the distinctive merits of label-free, immobilization-free, and split-mode readout. The mechanism revealed here provided a totally different perspective for signal transduction in cathodic photoelectrochemistry. Hopefully, it may stimulate more interests in the design and construction of semiconductor/transporter counterparts for exquisite operation of photocathodic bioanalysis.

Intercalated doxorubicin acting as stimulator of PbS photocathode for probing DNA-protein interactions

Label-free and turn-on DNA-binding protein detection based on the doxorubicin (Dox)-intercalated DNA as a signal stimulator in cathodic photoelectrochemistry is reported. The double-stranded DNA (dsDNA) acted as the matrix accommodating the intercalative Dox and allowed its effective photoelectrochemical (PEC) communication with the PbS quantum dots (QDs) for realizing cathodic photocurrent readout. In the presence of the target of the vascular endothelial growth factor (VEGF), the dsDNA was prevented from being digested by the exonuclease III (Exo III), allowing the anchor of Dox to perform as activation stimuli of the photocurrent. The VEGF can be detected in the linear range from 1.5 pM to 100 nM, with an impressively low detection limit of 0.49 pM. This study hints the prospect of DNA intercalated architectures as innovative signaling transduction elements for wide and versatile cathodic PEC bioassays. Effective signaling molecules that are conducive to probe-related cathodic PEC bioassays using DNA as the recognition or signification elements are scarce but very demanding. Herein, the doxorubicin intercalated in duplex DNA functions as an efficient signal stimulator of PbS-consisted photocathode, and thus hints the versatility of the strategy for various targets through cathodic photoelectrochemistry.

The in situ formation of a hole-transporting material on bismuth tungstate for innovative photoelectrochemical aptasensing

We present the in situ formation of a hole-transporting material (bismuth hexacyanoferrate) on the surface of bismuth tungstate aimed at an innovative photoelectrochemical strategy. This approach enabled a competent aptasensing platform for chloramphenicol that was amenable to homogenous, label-free, and split-mode detection.

[A rare anatomical variation of ileocolic veins involving in gastrocolic vein trunk: case report and literature review]

Objective: Due to its various anatomical variations and numerous branches, the gastrocolic vein trunk (Henle trunk) is the most common site to develop bleeding and other complications in laparoscopic right hemicolectomy for colon cancer. This study aims to investigate the role of ileocolic vein (ICV) joining with Henle trunk, a rare anatomical variation. Methods: A rare case whose ICV was newly found to involve in the formation of Henle trunk during laparoscopic resection of right hemicolon cancer was reported as right gastroepiploic vein+ right colic vein+superior right colic vein+ICV. This anatomical variation was confirmed by multi-slice spiral CT coronal two-dimensional reconstruction of right hemicolon angiography. The literatures about ICV participating in formation of Henle trunk were systematically searched from PubMed, The Cochran Library, CNKI net and Wanfang database, and the occurrence probability and composition of its anatomical variation were analyzed. Results: This was a 47-year-old female patient who underwent laparoscopic right hemicolectomy. When the vessels were dissected during operation, it was found that ICV did not accompany the ileocolic artery, but directly flowed into Henle trunk. Two-dimensional reconstructed CT images of right hemicolon vessels showed that the composition of Henle trunk was rarely varied, which was composed of right gastroepiploic vein, right colonic vein, superior right colonic vein and ICV. Five literatures were enrolled from literature retrieval. A total of 12 cases with ICV participating in the construction of Henle trunk were reported, with a probability of 0.27%-6.31% and 6 forms of the formation of Henle trunk. In this case, Henle trunk was made up of right gastroepiploic vein, right colonic vein, upper right colonic vein and ICV, which was reported for the first time. Conclusions: ICV involving in Henle trunk is a rare vascular variation, and this type of variation should be fully recognized. Careful dissection during operation is necessary to prevent intraoperative bleeding caused by improper operation.

[Anatomical controversies involved in radical resection of rectal cancer]

The concept of total mesorectal resection provides a quality control standard that can be followed for radical resection of rectal cancer, but some anatomical problems are still controversial. Compared with traditional open surgery, laparoscopic radical rectal surgery has better surgical vision, better neurological protection, better operating space. However, if the surgeon has insufficient understanding of the anatomy, collateral damage may occur, such as uncontrollable bleeding during the operation, postoperative urination and defecation dysfunction and so on. Based on the interpretation of the researches at home and abroad, combined with the clinical experience, we elucidate some associated issues, including anatomic variation of inferior mesenteric vessels, the controversy of inferior mesenteric artery ligation plane, the controversy of lymph node dissection in No. 253, the anatomical variation of middle rectal artery, and the anatomical controversy of lateral lymph node dissection in rectal cancer, in order to provide better cognitive process for the clinical front-line surgeons.

Smart nanozyme of silver hexacyanoferrate with versatile bio-regulated activities for probing different targets

Smart nanozymes that can be facile and rapidly produced, while with efficiently bio-regulated activity, are attractive for biosensing applications. Herein, a smart nanozyme, silver hexacyanoferrate (Ag₄[Fe(CN)₆]), was constructed in situ via the rapid, direct reaction between silver(I) and K₄[Fe(CN)₆]. And the activity of the nanozyme can be rationally modulated by different enzymatic reactions including the glucose oxidase (GOx, taken as a model oxidoreductase), alkaline phosphatase (ALP), and acetylcholinesterase (AChE). On the basis of which, a multiple function platform for the highly sensitive detection of glucose, ALP and AChE were developed through colorimetry. Corresponding detection limits for the above three targets were found to be as low as 0.32 μM, 3.3 U/L and 0.083 U/L (S/N = 3), respectively. The present study provides a novel nanozyme that can be produced in situ, which rules out the harsh, cumbersome, and time-consuming synthesis/purification procedures. In addition, it establishes a multiple function platform for the amplified detection of versatile targets by the aid of the developed nanozyme, whose detection has the advantages of low cost, ease-of-use, high sensitivity, and good selectivity.

Label-free and highly sensitive detection of DNA adenine methylation methyltransferase through cathodic photoelectrochemistry

In this work, we report the first exploration of cathodic photoelectrochemistry for the determination of the activity of DNA adenine methylation (Dam) methyltransferase (MTase). In this sensing system, potassium ferricyanide (K3[Fe(CN)6]) can greatly stimulate the photocurrent of a CdS quantum dot (QD) sensitized NiO (NiO/CdS) photocathode. After immobilization of the hairpin DNA probe on the electrode surface, its high steric hindrance and the electrostatic repulsion block the access of K3[Fe(CN)6] to the electrode surface, leading to depressed photocurrent of the photocathode. Once the hairpin DNA probe is methylated by Dam MTase, it can be recognized and cleaved by Dpn I, and then further digested by (Exo I), ultimately leading to the removal of the hairpin DNA probe from the electrode surface. This configurational change induces the decrement of steric hindrance/electrostatic repulsion effects and allows the efficient flux of K3[Fe(CN)6] to the photoelectrode for photocurrent stimulation. The cathodic PEC assay is presented in the "turn-on" mode, which can detect Dam MTase in the linear range from 0.04 to 100 U mL-1, with a detection limit as low as 0.028 U mL-1. In principle, the platform presents a promising method for probing various biomolecules that can lead to configuration or charge variations at the electrode surface, which may become a general strategy for versatile targets.

Establishing Interfacial Charge-Transfer Transitions on Ferroelectric Perovskites: An Efficient Route for Photoelectrochemical Bioanalysis

This work presents the concept of establishing interfacial charge-transfer transitions (ICTT) on ferroelectric perovskites for efficient photoelectrochemical (PEC) bioanalysis. The model system was exemplified by using representative lead titanate (PbTiO₃) and an enzyme tandem consisting of the isocitrate dehydrogenase (ICDH) and p-hydroxybenzoate hydroxylase (PHBH). The enzymatic generation of protocatechuic acid (PCA) can coordinate onto the surface of the PbTiO₃ and hence form the ICTT that enables direct ligand-to-metal charge transfer from the highest occupied molecular orbital (HOMO) of PCA to the conduction band (CB) of PbTiO₃ under light irradiation. Due to the ferroelectric polarization induced electric field of PbTiO₃ and the surface polarity of PCA modification, enhanced charge separation of the ICTT contributes to the generation of anodic photocurrent and thus underlies a unique route for detecting the enzymatic activity or its substrate. For dehydrogenase detection, this strategy has better performance than some classical methodologies in terms of high sensitivity and improved selectivity. This work not only features ICTT establishment on ferroelectric perovskites for unique bioanalysis but also provides new insights into the utilization of ferroelectric perovskites for advanced PEC bioanalysis.

[Chemical composition of body extracts from Apriona germari and its function in sexual communication]

To elucidate the composition of semiochemicals of Apriona germari and its function in sexual communication, GC-MS was used to detect the composition of semiochemicals of the overall body and the end abdominal tissue extracts in A. germari. Y-tube olfactometer was used to determine the olfactory response of adult female and male to the standard compounds of the five main extracts. The contact reaction test with male and female adults was performed to the eluted adults that smeared tandard compounds. The results showed that the main ingredients of semiochemicals were alkanes and alkenes with more than 10 carbons. Concentration of (Z)-9-Tricosene was the highest, followed by heptacosane, nonacosane, nonadecene, octacosane, 9-Hexylheptadecane, aldehyde, and ester. Results of the olfactory reaction showed that nonacosane had a significant attractivity to both male and female adults, and that heptacosane had a significant attractivity only to female adults. Nonadecene had a extremely significant repellent activity to female adults. 1-docosene and (Z)-9-Tricosene had no evident role to the male and female adults. Results of the contact test showed that male adults had the strongest courtship responses to the eluted adults with 1-docosene, heptacosane and nonacosane. Female adults had the strongest courtship responses to the eluted adults with nonacosane. Our results indicated that 1-docosene, heptacosane, and nonacosane were important component of the sex pheromone of A. germari, which played an important role in the sexual communication.

Photocatalytic and Luminescent Sensing Properties of Two New 1D Zn(II)-Based Coordination Polymers

Two new d¹⁰-configuration based Zn(II) coordination polymers with formula [Zn²(L)²(2,2'-bipy)₂]_n (1) and [Zn₂(L)₂(4,4'-bipy)]_n (2) (H₂L = 4,4'-{[1,2-phenylenebis-(methylene)]bis(oxy)}dibenzoic acid, 2,2'-bipy= 2,2'-bipyridine and 4,4'-bipy= 4,4'-bipyridine) have been synthesized and characterized. Both the compounds had been used as possible luminescent sensors for detecting nitroaromatic compounds (NACs) and as photocatalysts to photodegrade methyl violet (MV) under UV irradiation. The sensing experiments indicated that 2 displayed selective sensing for m-nitrophenol (MNP) with lower limit of detection (LOD) of 1.14 ppm while photocatalytic experiments indicated that 1 displayed better photocatalytic performance than 2 in photodegrading MV.

Piezoelectric modulation of broadband photoresponse of flexible tellurium nanomesh photodetectors

Flexible photodetector shows great potential applications in intelligent wearable devices, health monitoring, and biological sensing. In this work, single crystal β-tellurium nanowires were grown on flexible muscovite by molecular beam epitaxy, constructing high-density ordered nanomesh structure. The prepared photodetectors based on tellurium nanomesh exhibit excellent mechanical flexibility, fast response in a broad range from ultraviolet to near-infrared, and good photosensitivity. We found that the flexible photodetectors with Shottky contact drastically suppressed dark current, while the response speed was lowered in comparison to the devices with ohmic contact, as holes would take a long time to tunnel through the Shottky barrier between metal and p-type Te. Moreover, the photoresponse of flexible Shottky photodetectors can be modulated by piezoelectricity of tellurium, and pronounced photocurrent increase after bending many times. Under external stress, polarization charges could tune Shottky barrier height of the metal/tellurium, resulting in variation of photocurrent. This research not only explores the broadband photoresponse and piezoelectric effect of tellurium nanomesh, but also promotes the integration and development of broadband flexible optoelectronic devices.

Versatile enzymatic assays by switching on the fluorescence of gold nanoclusters

Herein we present a general and turn-on strategy for enzymatic bioassays on the basis of redox state dependent emission of gold nanoclusters (AuNCs). The photoluminescence of AuNCs was quenched obviously by the oxidative ferricyanide while unaffected by its corresponding reduced state, i.e., ferrocyanide. The distinctive quenching abilities for AuNCs by the redox couple (ferricyanide/ferrocyanide) enabled their utility as new fluorescent sensing platforms to detect redox-related phenomena. The proposed protocols were conducted by using the model oxidoreductases of glucose oxidase (GOx) and the enzyme cascade of lactate dehydrogenase (LDH)/diaphorase to catalytically convert ferricyanide to ferrocyanide, which switched on fluorescence of the detection systems. The detection limit for glucose and lactate was found to be as low as 0.12 and 0.09 μM, respectively. This work features the first use of the redox couple of ferricyanide/ferrocyanide in fluorescent bioanalysis, which enables versatile, signal on and highly sensitive/selective detections as compared to the state of the art fluorescently enzymatic sensing platforms. Importantly, considering the significance of ferricyanide/ferrocyanide involves in numerous other oxidoreductases mediated biocatalysis, this protocol has wide versatility that enables combination with oxidoreductases related reactions for biosensing.

Immobilization-free, split-mode cathodic photoelectrochemical strategy combined with cascaded amplification for versatile biosensing

We propose herein an immobilization-free, split-mode cathodic photoelectrochemical (PEC) strategy coupled with a cascaded amplification for versatile biosensing. Taking DNA and microRNA (miRNA) as the model targets, the hybridization between the targets and the hairpin probe triggers the digestion of the probe DNA by T7 exonuclease (T7 Exo), thus to generate G-quadruplex (G4) forming sequences, and then the released targets (DNA or miRNA) initiate the subsequent cycling processes and generate a large amount of G4 forming sequences. Subsequently, the formed G4 sequences associate with hemin to form the G4/hemin DNAzyme, which catalytically produces 1,4-bezoquinone (BQ) for conjugating onto the surface of the chitosan (CS) deposited BiOI/ITO photocathode via the quinone-chitosan conjugation chemistry (QCCC). Under photo excitation, the covalently attached quinones can act as electron acceptors of bismuth oxyiodine (BiOI), promoting the photocurrent generation and thus allowing the elegant and "signal-on" mode for probing targets of interest. Highly sensitive and selective PEC bioassays are readily realized, with the detection limits down to 2.2 fM (for DNA) and 0.2 fM (for miRNA). Since no labeling and no electrode modification processes are needed, this split-mode PEC biosensing strategy is amenable to convenient, time/labor saving, and high-throughput detections. More significantly, it provides a novel concept to design immobilization-free and label-free cathodic PEC biosensing systems, and showcases promise in general and versatile bioanalysis research.

[Clinical characteristics of 84 children with invasive Haemophilus influenzae infection from 2014 to 2018]

Objective: To investigate the clinical characteristics of invasive Haemophilus influenzae (HI) infection in children. Methods: The clinical manifestations, laboratory examinations and treatment outcomes of 84 children with HI infection confirmed by bacterial culture in 7 tertiary children's hospitals from 2014 to 2018 were analyzed retrospectively. Results: Among the 84 cases, 50 were males. The age was 1.54 years (ranged from 5 days to 13 years).Twenty cases (24%) had underlying diseases and 48 cases (57%) had not received antibiotics before collecting specimens. Eighty-two cases (98%) had fever and 75 cases (89%) had clear infection foci, among which 31 cases (37%) had meningitis and 27 cases (32%) had pneumonia. Blood culture was positive in 62 cases (74%), cerebrospinal fluid culture was positive in 10 cases (12%), blood culture and cerebrospinal fluid culture were both positive in 11 cases (13%). Antibiotics susceptibility test showed that 27% (22/82) of all HI strains produced β-lactamases and 48% (37/77) strains were resistant to ampicillin. The drug resistance rates to cefuroxime, ampicillin-sulbactam, trimethoprim-sulfamethoxazole and azithromycin were 25% (20/80) , 20% (9/45) , 71% (44/62) and 19%(11/58), respectively. All strains were sensitive to meropenem, levofloxacin and ceftriaxone. After sensitive antibiotic therapy, 83% (70/84) of all patients were cured and improved, the mortality rate and loss of follow-up rate were 13% (11/84) and 4% (3/84) respectively. Conclusions: Meningitis and pneumonia are common presentation of invasive HI infections in children. Mortality in HI meningitis children is high and the third generation of cephalosporins, such as ceftriaxone can be used as the first choice for the treatment of invasive HI infection.

In situ chemical redox and functionalization of graphene oxide: toward new cathodic photoelectrochemical bioanalysis

This report outlines the first exploration of graphene oxide (GO) itself as a light harvesting material with an innovative in situ chemical redox and functionalization (CRF) strategy for versatile and high-throughput cathodic photoelectrochemical (PEC) bioanalysis.

[Comparison of various imaging in the diagnosis of renal cell carcinoma with inferior vena cava tumor thrombus combined with bland thrombus]

OBJECTIVE

To analyse the clinical and imaging data of patients with renal cell carcinoma (RCC) with inferior vena cava tumor thrombus (IVCTT), and to assess the diagnostic efficacy of ultrasound, enhanced computed tomography (CT) and enhanced magnetic resonance imaging (MRI) in the diagnosis of RCC with IVCTT combined with bland thrombus was assessed.

METHODS

We retrospectively analyzed the clinical and imaging data of 56 RCC patients with IVCTT who underwent radical nephrectomy and IVC thrombectomy between January 2014 and July 2018 in Department of Urology, Peking University Third Hospital. All the patients underwent US, enhanced CT and enhanced MRI preoperatively, and all the cases were confirmed with RCC with IVCTT by histological evaluation.

RESULTS

The criteria of RCC with IVCTT combined with bland thrombus was confirmed by intraoperative observation and postoperative pathology. The 56 patients were divided into bland thrombus group (n=18) and non bland thrombus group (n=38). Compared the two groups, it was found that the length of IVCTT was longer [(10.50 ± 5.55) cm vs.(6.66 ± 3.73) cm, P=0.014]; the ratio of diameter of IVCTT to maximum coronal diameter of IVC was closer to 1 [1.0 (0.7, 1.0) vs. 0.9 (0.2, 1.0), P=0.004]; the proportion of lower limb edema was higher [66.7(12/8)% vs.5.3%(2/36), P=0.005]；the proportion of segmental resection or interrupt of IVC was higher [66.7%(12/18) vs.15.8%(6/38), P<0.001], with statistical significance. Compared with the three imaging methods of US, enhanced CT and MRI, the highest sensitivity was MRI (77.8%), the highest specificity was enhanced MRI and enhanced CT (97.4%), the highest accuracy was enhanced CT and enhanced MRI (83.9%), the highest positive predictive value was enhanced CT (90.9%) and the highest negative predictive value was enhanced MRI (89.2%).

CONCLUSION

For the patients that RCC with IVCTT combined with bland thrombus, the length of IVCTT is longer, and the ratio of the diameter of IVCTT to the maximum corona diameter of IVC is closer to 1, and more likely to cause lower limb edema. Preoperative comprehensive evaluation of multiple images is needed to improve the accuracy of diagnosis.

[Diagnosis and surgical treatment of massive adrenal area tumor with tumor thrombus]

OBJECTIVE

To summarize the experience of diagnosis and operation related to massive adrenal area tumor with venous tumor thrombus in clinic.

METHODS

From October 2017 to March 2019, a total of 8 cases of massive adrenal area tumor (>7 cm) with venous tumor thrombus were admitted at Peking University Third Hospital including 5 males and 3 females with mean age 50.6 years (31-62 years). There were 6 cases on the right side and 2 cases on the left side. The first symptoms included abdominal discomfort, hypertension, Cushing syndrome and abnormal menstruation; special past history included cirrhosis and lung cancer. Computed tomography (CT) and routine endocrine hormone tests were examined. Preoperative imaging confirmed 5 cases masses with tumor thrombus in inferior vena cava (IVC) and 1 case with tumor thrombus in left renal vein. Two cases presented with tumor thrombus in central adrenal vein were found intraoperatively. Open adrenalectomy and thrombectomy were performed in 4 cases of right side complicated with high tumor thrombus of inferior vena cava. Laparoscopic adrenalectomy and thrombectomy were performed in 3 cases, including 2 cases on the right and 1 case on the left. The case with tumor thrombus in left renal vein gave up operation. The patients were followed up with outpatient and telephone.

RESULTS

The mean size of the tumor was 8.9 cm (7-11 cm), the mean operative time was 319 min (120-510 min), while the estimated blood loss was 629 mL (50-1 200 mL). Intraoperative blood transfusion was required in 2 cases and 1 case encountered wound infection. The pathological types included pheochromocytoma, adrenocortical carcinoma, adrenal metastases of haptic carcinoma, and leiomyosarcoma. The case with left lung carcinoma who underwent left pneumonectomy one month before was highly suspected adrenal metastases of lung carcinoma. Tumor thrombus of pheochromocytoma was combined with blood thrombus. Capsule of adrenocortical carcinoma was fragile in adrenocortical carcinoma. Abundant blood supply existed in adrenal metastases. The leiomyosarcoma had unabundant blood supply and invaded IVC to form tumors thrombus. The mean follow-up time was 8.4 months (1-15 months). One case with adrenocortical carcinoma died after 1 year in the follow-up.

CONCLUSION

We present the rare cases of different pathological types of massive adrenal tumors with tumor thrombus extending into the IVC extension or other vein. Preoperative diagnosis needs comprehensive evaluation and perfect preoperative preparation. Surgery is difficult and varied. Open approach as well as retroperitoneal laparoscopic approach is feasible.

[Impact of diagnostic ureteroscopy and biopsy on radical nephroureterectomy of upper tract urothelial carcinoma]

OBJECTIVE

To investigate the impact of preoperative diagnostic ureteroscopy and biopsy (UB) on radical nephroureterectomy (RNU) and the prognosis of upper tract urothelial carcinoma (UTUC).

METHODS

The clinical data of UTUC patients receiving RNU between Jan. 2007 and Dec. 2016 were retrospectively collected. The median follow up time was 40 months. The operation time and blood loss of RNU were compared between UB group and non-UB group. Subgroup analyses were conducted according to the time interval between UB and RNU, and surgery methods of lower ureter. The linear regression model was used to adjust for other common factors that impacted operation time.

RESULTS

A total of 163 UTUC patients were included in the final analysis. For the lower ureter, open ureterectomies were performed in 91 patients (55.9%), while retroperitoneal laparoscopic ureterectomies were performed in 72 patients (44.1%). A total of 110 (67.5%) patients received preoperative UB. Compared with non-UB group, the average operation time of UB group was significantly longer [(252.5±79.8) min vs. (221.3±79.8) min, P=0.019], but no difference of blood loss was found (median, 50 mL vs. 50 mL, P=0.143). In subgroup analysis, the average operation time of RNU was significantly prolonged when RNU was performed after 1 week of UB (P=0.023). Meanwhile, the median blood loss of RNU increased significantly when it was done after 2 weeks of UB compared with non-UB group (100 mL vs. 50 mL, P=0.012). UB was also significantly prolonged the operation time of RNU in retroperitoneal laparoscopic ureterectomy group (P=0.012). In multivariable analysis, UB (P=0.049), ≥pT3 (P=0.039), pN+ (P=0.018) and ureterectomy method (P=0.005) were independent risk factors of prolonged operation time. The 3-year cancer specific survival (CSS) rate was 87.2% in our cohort. UB had no significant impact on cancer specific survival (P=0.435).

CONCLUSION

UB was an independent risk factor of prolonged RNU time, but did not significantly influence cancer specific survival of upper tract urothelial carcinoma patients.

The Pilot Study of Spectral CT for the Diagnosis of Mediastinal Lymph Node Metastasis in Primary Lung Cancer

Objective: To investigate the application value of spectral CT for the diagnosis of mediastinal lymph node metastasis in primary lung cancer. Materials and Methods: 32 patients who had primary lung cancer with 90 enlarged mediastinal lymph nodes underwent spectral CT by using gemstone spectral imaging (GSI) mode. The spectral curves of regions of interest (ROI) in primary lung cancer and mediastinal lymph nodes were measured with GSI post-processing software. The spectral curve slope between 40 and 140 keV was calculated and compared between them for the diagnosis of mediastinal lymph node metastasis. The data were divided into metastatic group (group A) and non-metastatic group (group B) according to the pathologic findings. SPSS17.0 software with paired sample t test was used for statistical analysis and P < 0.05 was considered statistically significant difference. Results: The spectral curve slopes in primary lung cancer and mediastinal lymph node in group B were 0.96 ± 0.13 and 1.32 ± 0.17. There was significant difference between them (t = –2.68, P < 0.05). While there was no significant difference between them in group A (t = –1.62, P > 0.05) with the values of 1.06 ± 0.09 and 1.09 ± 0.12. The accuracy, sensitivity and specificity of diagnosing mediastinal lymph node metastasis were 84.21%, 86.67% and 82.77%, respectively in line with spectral curve. Conclusions: Spectral CT, as a new and non-invasive method, has valuable effect for the diagnosis of mediastinal lymph node metastasis in pre-operative staging of lung cancer.

[Spectrometric analyses of larotaxel and larotaxel liposomes quantification by high performance liquid chromatography]

OBJECTIVE

Larotaxel is a new chemical structure drug, which has not been marketed worldwide. Accordingly, the standard identification and quantification methods for larotaxel remain unclear. The spectrometric analyses were performed for verifying weight molecular formula, molecular weight and chemical structure of larotaxel. Besides, a quantification method was developed for measuring larotaxel in the liposomes.

METHODS

The molecular formula, molecular weight and chemical structure of larotaxel were studied by using mass spectrometry (MS), infra-red (IR), nuclear magnetic resonance (NMR) and ultraviolet-visible (UV-vis) spectrometric techniques. The absorption wavelength of larotaxel was investigated by UV-vis spectrophotometry full-wavelength scanning. Besides, a quantification method was developed by high performance liquid chromatography (HPLC), and then validated by measuring the encapsulation efficacy of larotaxel liposomes.

RESULTS

The four spectral characteristics of larotaxel were revealed and the corresponding standard spectra were defined. It was confirmed that larotaxel had the structure of tricyclic diterpenoids, with the molecular formula of C45H53NO14, the molecular weight of 831.900 1, and the maximum absorption wavelength of 230 nm. The quantitative method of larotaxel was established by using HPLC with a reversed phase C18 column (5 μm, 250 mm×4.6 mm), a mobile phase of acetonitrile-water (75:25, volume/volume), and a detection wavelength of 230 nm. The validation study exhibited that the established HPLC method was stable, and had a high recovery and precision in the quantitative measurement of larotaxel in liposomes. In addition, a new kind of larotaxel liposomes was also successfully prepared. The particle size of the liposomes was about 105 nm, with an even size distribution. And the encapsulation efficiency of larotaxel in the liposomes was above 80%.

CONCLUSION

The present study offers reference standard spectra of larotaxel, including MS, IR, NMR, and UV-vis, and confirms the molecular formula, molecular weight and chemical structure of larotaxel. Besides, the study develops a rapid HPLC method for quality control of larotaxel liposomes.

[Clinical analysis of eosinophilic gastroenteritis in 71 children]

Objective: To summarize the clinical data including manifestations, diagnosis, treatment and prognosis of eosinophilic gastroenteritis (EGE) in children. Methods: A retrospective analysis was performed in 71 patients with pathologically proven EGE at Beijing Children's Hospital Affiliated to Capital Medical University from January 2008 to January 2017. Their clinical manifestations, laboratory and imaging examinations, endoscopic findings, histopathological examinations, and treatment were collected and analyzed. Results: Among 71 EGE cases, 47 (66%) cases were male and 24 (34%) cases were female, and the median age was 9.2 (0.2-16.5) years old. The main clinical manifestations included abdominal pain (76%, 54/71), vomiting (68%, 48/71), anorexia (54%, 38/71), weight loss (38%, 27/71), and diarrhea (37%, 26/71). There were 27 cases (38%) with a history of allergic diseases or family history. The median absolute value of eosinophil in peripheral blood of the 71 patients was 0.4 (0-36.8)×10(9)/L, and 27 cases (38%) showed an increase in eosinophil counts. Serum IgE was measured in 52 patients (104.3 (3.4- 3 000.0)×10(3) U/L), and 30 patients (58%) showed an increase in serum IgE. A large number of eosinophils ((41.0±8.5)/HP) were found in 3 patients' ascites. The endoscopic examination of upper gastrointestinal tract revealed hyperemic edema in 62 cases (87%), plaque in 44 cases (62%), erosion in 17 cases (24%) and ulceration in 16 cases (23%). Histopathologically, in 8 cases (11%) the disease involved both stomach and duodeneum, in 21 cases (30%) involved stomach only, and in 37 cases (52%) involved duodeneum only. In addition, in 6 cases (8%) the disease involved esophagus and in 10 cases (14%) involved colorectum. Microscopically, eosinophil counts averaged 67/HP, 33/HP, 40/HP and 38/HP in esophageal, gastric, duodenal and colorectal mucosa respectively. A total of 34 cases were treated with glucocorticoid, and all these patients had alleviation of symptoms, which occurred within 14.9 days on average, but EGE recurred in 11 cases (32%). Conclusions: The clinical symptoms and endoscopic findings of EGE are diverse and nonspecific. Histopathological examination of gastrointestinal mucosa is particularly important for the diagnosis. Glucocorticoid treatment is effective, but the patients with EGE are prone to relapse.

[Single-center study of laparoscopic radical nephrectomy with Mayo 0-2 level inferior vena cava thrombectomy]

OBJECTIVE

To investigate the safety and feasibility of laparoscopic treatment for renal carcinoma with Mayo 0-2 level venous thrombosis.

METHODS

From January 2015 to February 2018, 58 renal carcinoma cases with venous thrombus underwent laparoscopic radical nephrectomy with inferior vena cava thrombectomy in Department of Urology, Peking University Third Hospital, of which, 51 cases were male, and 7 female, aged 29-82 years. According to the Mayo grade classification, 20 cases were level 0, 20 cases were level 1, and 18 cases were level 2, with left side being 22 cases, and right side 36 cases. The patients except for those complicated with hemorrhagic diseases, cardiac and pulmonary insufficiency, or those who could not tolerate anesthesia and surgical contraindications, underwent the operation after comprehensive examinations.

RESULTS

The 58 cases of renal tumor with venous tumor emboli were successfully completed with the surgeries, including 50 cases of totally laparoscopic surgery, 8 cases of laparoscopy surgery from convert to open (among the patients who were converted to open surgery, 7 were complicated with grade 2 tumor thrombus and 1 with grade 1 tumor thrombus). The main reasons for converting to open surgery were huge tumors (the largest of which was about 16 cm in diameter), severe adhesion and difficulty of separation. For different patients, different surgical methods and procedures were adopted according to the tumor direction and the different grade of tumor thrombus. Radical nephrectomy combined with vena cava tumor thrombus removal was performed in 55 cases and segmental resection of vena cava in 3 cases. The operation time was 132-557 min, and blood loss was 20-3 000 mL. Post-operative pathological types: 51 cases were clear cell carcinoma, 5 cases were type 2 of papillary carcinoma, 1 case was squamous cell carcinoma, and 1 case was chromophobe cell tumor. In the study, 47 cases were followed up for 1-36 months, and 4 cases died (the survival time was 5-15 months, with an average of 10.2 months).

CONCLUSION

Laparoscopic radical nephrectomy with inferior vena cava thrombectomy is a reasonable choice for renal tumor with Mayo 0-2 level venous thrombosis. For different tumor directions and different grades of tumor thrombus, an appropriate operation plan can give the maxim benefit to the patients with skillful surgeons.

Two dcm Gene Clusters Essential for the Degradation of Diclofop-methyl in a Microbial Consortium of Rhodococcus sp. JT-3 and Brevundimonas sp. JT-9

The metabolism of widely used aryloxyphenoxypropionate herbicides has been extensively studied in microbes. However, the information on the degradation of diclofop-methyl (DCM) is limited, with no genetic and biochemical investigation reported. The consortium L1 of Rhodococcus sp. JT-3 and Brevundimonas sp. JT-9 was able to degrade DCM through a synergistic metabolism. To elaborate the molecular mechanism of DCM degradation, the metabolic pathway for DCM was first investigated. DCM was initially transformed by strain JT-3 to diclofop acid and then by strain JT-9 to 2-(4-hydroxyphenoxy) propionic acid as well as 2,4-dichlorophenol. Subsequently, the two dcm gene clusters, dcmAE and dcmB1B2CD, involved in further degradation of 2,4-dichlorophenol, were successfully cloned from strain JT-3, and the functions of each gene product were identified. DcmA, a glutathione-dependent dehalogenase, was responsible for catalyzing the reductive dehalogenation of 2,4-dichlorophenol to 4-chlorophenol, which was then converted by the two-component monooxygenase DcmB1B2 to 4-chlorocatechol as the ring cleavage substrate of the dioxygenase DcmC. In this study, the overall DCM degradation pathway of the consortium L1 was proposed and, particularly, the lower part on the DCP degradation was characterized at the genetic and biochemical levels.

A novel photoswitchable enzyme cascade for powerful signal amplification in versatile bioassays

This report outlines the construction of an advanced, exquisite photoswitchable enzyme cascade on the basis that tyrosinase (TYR) catalyzes the generation of dihydroxyphenylalanine (DOPA) coordinated TiO₂ nanoparticles (NPs) to form a light responsive nano-trigger that subsequently photoactivates the enzymatic activity of horseradish peroxidase (HRP). This photoswitchable enzyme cascade has a powerful signal transduction/amplification ability in TYR-based bioassays, and holds great promise to be applied in versatile applications.