Two-Dimensional Metal-Organic Framework Nanosheets: Synthesis and Applications in Electrocatalysis and Photocatalysis.

Two-dimensional metal-organic nanosheets (2D MONs) are an emerging class of ultrathin, porous, and crystalline materials. The organic/inorganic hybrid nature offers MONs distinct advantages over other inorganic nanosheets in terms of diversity of organic ligands and metal notes. Compared to bulk three-dimensional metal-organic frameworks, 2D MONs possess merits of high density and readily accessible catalytic sites, reduced diffusion pathways for reactants/products, and fast electron transport. These features endow MONs with enhanced physical/chemical properties and are ideal for heterogeneous catalysis. In this Review, state-of-the-art synthetic methods for the fabrication of 2D MONs were summarized. The advances of 2D MONs-based materials for electrocatalysis and photocatalysis, including hydrogen evolution reaction (HER), oxygen evolution reaction (OER), oxygen reduction reaction (ORR), carbon dioxide reduction reaction (CO2 RR), and electro-/photocatalytic organic transformations were systematically discussed. Finally, the challenges and perspectives regarding future design and synthesis of 2D MONs for high-performance electrocatalysis and photocatalysis were provided.

Symptomatic features and prognosis of 932 hospitalized patients with coronavirus disease 2019 in Wuhan.

OBJECTIVE: To discern the symptomatic features of coronavirus disease 2019 (COVID-19) and to evaluate the severity and prognosis of the disease. METHODS: In this retrospective cohort study, 932 hospitalized patients with COVID-19 in Wuhan were enrolled, including 52 severe and 880 non-severe cases. All patients were followed up for 3 months after discharge. The symptomatic features and follow-up data of the patients in both groups were analyzed and compared. RESULTS: Of the 932 patients, fever (60.0%), cough (50.8%) and fatigue (36.4%) were the most common symptoms. In total, 32.7% of the severe cases presented with gastrointestinal symptoms at disease onset, including anorexia, nausea, vomiting or diarrhea, which was significantly higher than that of the non-severe group (P = 0.0015). The incidence of olfactory disturbance and dysgeusia was only 3.1% and 6.2%, respectively. After adjusting for age and sex, multivariate regression analysis showed that fever lasting for over 5 days (odds ratio [OR] 1.90, 95% confidence interval [CI] 1.00-3.62, P = 0.0498), anorexia at onset (OR 2.61, 95% CI 1.26-5.40, P = 0.0096), and modified Medical Research Council level above grade 2 when dyspnea occurred (OR 14.19, 95% CI 7.01-28.71, P < 0.0001) were symptomatic risk factors for severe COVID-19. During the follow-up, cough (6.2%), dyspnea (7.2%), fatigue (1.8%), olfactory disturbance and dysgeusia (1.5%) were the significant remaining symptoms. CONCLUSIONS: COVID-19 causes clusters of symptoms with multiple systems involved. Certain symptomatic characteristics have predictive value for severe COVID-19. Short-term follow-up data reveal that most patients have a good prognosis.

Notch1-ADAM8 positive feed-back loop regulates the degradation of chondrogenic extracellular matrix and osteoarthritis progression.

BACKGROUND: Osteoarthritis (OA) is one of the most prevalent joint disease, and there are still no effective therapeutic agents or clinical methods for the cure of this disease to date. The degradation of cartilage extracellular matrix (ECM) is a major cause of OA. METHOD: IL-1ß was used to induce chondrogenic degradation. Q-PCR and Western blotting were used to detect mRNA and protein level, respectively. ELISA was used to detect the secreted TNF-α and IL-6 level. Immunofluorescence was used to detect the protein level of Aggrecan, Collagen II and ki67. TUNEL and flow cytometry were used to examine cell apoptosis of chondrocytes. ChIP and luciferase assay were used to study molecular gene regulation. Osteoarthritic animal model and Safranin-O staining were used to determine the in vivo OA phenotype. RESULTS: The expression of ADAM8 was up-regulated in osteoarthritic chondrocytes. Knockdown of ADAM8 suppressed the OA phenotype in the in vitro OA cell model. ADAM8 regulated OA progression through the activation of EGFR/ERK/NF-κB signaling pathway. Inhibition of Notch signaling suppressed OA phenotype in the in vitro OA cell model. Notch signaling regulated the gene expression of ADAM8 directly via Hes1. Notch1-ADAM8 positive feedback loop promoted the progression of OA in vivo. CONCLUSION: Notch1-ADAM8 feed-back loop regulates the degradation of chondrogenic extracellular matrix and osteoarthritis progression.

[Treatment of grade I and II degree degenerative lumbar spondylolisthesis with minimally invasive surgery-transforaminal lumbar interbody fusion under Quadrant channel].

OBJECTIVE: To investigate the advantages of minimally invasive surgery-transforaminal lumbar interbody fusion(MIS-TLIF) under Quadrant channel in the treatment of grade I and II degree degenerative lumbar spondylolisthesis. METHODS: The clinical data of 100 patients with grade I and II degree degenerative lumbar spondylolisthesis treated from March 2014 to March 2017 were retrospectively analyzed. Among them, 50 patients were treated with MIS-TLIF, including 19 males and 31 females, aged from 44 to 73 years old with an average of (49.83±15.46) years old; course of disease from 6 months to 7 years with the mean of (22.18±4.74) months; L4 slippage was in 30 cases and L5 slippage was in 20 cases, the slippage vertebral pedicles were intact; according to Meyerding classification, 29 cases of I degree slip and 21 cases of II degree slip. Other 50 patients were treated with open-transforaminal lumbar interbody fusion(OPEN-TLIF), including 23 males and 27 females, aged from 40 to 77 years old with an average of(50.67±14.36) years old; course of disease from 6 months to 10 years with the mean of (20.56±5.37) months; L4 slippage was in 33 cases and L5 slippage was in 17 cases, the slippage vertebral pedicles were intact; according to Meyerding classification, 34 cases of I degree slip and 16 cases of II degree slip. The operation time, length of surgical incision, intraoperative blood loss, postoperative drainage, and serum creatine kinase(CK-MM) levels before surgery and 1 day after surgery were observed. Visual analogue scale(VAS), Japanese Orthopedic Association Score (JOA), and Oswestry dysfunction index (ODI) were compared between the two groups before and after surgery. According to the imaging data, the slip rate, intervertebral space height and slip angle of the two groups before and 12 months (last follow-up) were compared. Intervertebral fusion was evaluated according to lumbar X-ray and CT at 6 and 12 months postoperatively. The clinical effect was evaluated according to the MacNab criteria at 12 months after surgery. RESULTS: All the patients were followed up for 12 months. In MIS-TLIF group, operation time, length of surgical incision, intraoperative blood loss, postoperative drainage were (118.48±21.97) min, (3.74±0.74) cm, (148.78±32.32) ml, (84.85±16.37) ml, respectively, CK-MM level was (72.31±9.79) µ/L before surgery and (415.12±25.89) µ/L at the first day after surgery. In OPEN-TLIF group, operation time, length of surgical incision, intraoperative blood loss, postoperative drainage were (115.40±11.94) min, (8.46±0.69) cm, (219.27±48.33) ml, (157.69±31.61) ml, respectively, CK-MM level was (75.48±10.73) µ/L before surgery and (506.69±37.86) µ/L at the first day after surgery. The intraoperative blood loss, postoperative drainage volume, length of surgical incision, and CK-MM level on the first postoperative day were lower in MIS-TLIF group than in OPEN-TLIF group(P<0.05), but the operation time and preoperative CK-MM levels were compared between two groups, the difference was not statistically significant (P>0.05). There were no significant differences in ODI, VAS, and JOA scores before surgery(P>0.05). The ODI, VAS, and JOA scores were significantly improved after surgery(P<0.05), and the scores of MIS-TLIF group were better than those of OPEN-TLIF group(P<0.05). At the last follow-up, the slip rate, slip angle and intervertebral space height were significantly improved in the same group(P<0.05), but there was no significant difference between two groups(P>0.05). There was no significant difference in intervertebral fusion between groups at 6 and 12 months after operation(P>0.05). According to the MacNab standard, 40 cases got excellent results, 7 good, 3 fair in MIS-TLIF group, and 35 cases got excellent results, 10 good, 5 fair in OPEN-TLIF group. One patient had incision exudation and delayed healing in MIS-TLIF group. And in OPEN-TLIF group, 1 patient had local muscle necrosis on the right side of L5 and the bacterial culture of the secretions was negative in the different three times and the right internal fixation device was taken out after the second operation completely debridement, and finally obtained delayed healing. CONCLUSIONS: The MIS-TLIF under Quadrant channel has advantage of minimally invasive trauma, less bleeding, faster function recovery and better effect in surgical treatment of grade I and II degree degenerative lumbar spondylolisthesis.

Paracoccus zhejiangensis sp. nov., isolated from activated sludge in wastewater-treatment system.

A bacterial strain, designated J6(T), was isolated from activated sludge, collected from a chemical wastewater treatment system in Zhejiang Province of China. The cells stained Gram-negative, were aerobic, pale-yellow, and non-motile short rods. Phylogenetic analysis of the 16S rRNA gene sequence indicated that the closest relative of this organism was Paracoccus aminophilus KACC 12262(T) = JCM 7686(T) (97.4 % sequence similarity). Strain J6(T) grew at 10-37 °C (optimum 30 °C), at pH 6.0-8.0 (optimum pH 7.0) and with 0-5 % NaCl (optimum 3 %, w/v). The predominant cellular fatty acid found was summed feature 8(C18:1 ω7c and/or C18:1 ω6c; 82.8 %). The major respiratory quinone-detected was Q-10 and the DNA G+C content was 61.9 mol %. The polar lipid profile consisted of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylcholine and several unknown polar lipids. Strain J6(T) showed low DNA-DNA relatedness values with P. aminophilus KACC 12262(T) (28 ± 3 %). The phylogenetic analysis, DNA-DNA hybridization, whole-cell fatty acid composition as well as biochemical characteristics allowed clear differentiation of the isolate from the other type strains of already described Paracoccus species. It is evident from the genotypic, phenotypic and chemotaxonomic analyses that strain J6(T) should be classified as a novel species of the genus Paracoccus, for which the name P. zhejiangensis sp. nov. is proposed. The type strain is J6(T) (KACC 16703(T) = CCTCC AB 2012031(T)).

[Quantitative analysis of chlorophyll-a reflectance spectrum in red spectral region of water].

The chlorophyll-a concentration in waters is one of the main parameters of water color remote sensing in case II waters. There is a reflectance peak in red band region because of inherent optical properties. Based on the coefficients of absorption and backscattering of waters, colored dissolved organic matter (CDOM), tripton and chlorophyll-a, the reflectance of remote sensing was simulated according to the forward radiation transfer model without the consideration of fluorescence peak. The reflectance peak intensity and reflectance peak position at different wavelengths in red band region were analyzed with different chlorophyll-a concentration. There is a good linear relationship between the red reflectance peak intensity and chlorophyll-a concentration when the chlorophyll-a concentration is 1-50 microg x L(-1). But the linear relationship between the reflectance peak intensity and chlorophyll-a concentration will decrease with the increasing chlorophyll-a concentration. When chlorophyll-a concentration is up to 1 000 microg x L(-1), the logarithm relationship between the reflectance peak intensity and chlorophyll-a concentration is better than linear relationship. The wavelength position of reflectance peak in red band region will shift towards larger wave-length at logarithmic growth rate with increasing chlorophyll-a concentration, and the logarithm relationship will be more apparent with the inoreasing chlorophyll-a concentration. The same trend happens to the reflectance peak intensity and the wavelength position of peak in red region with different in-water constituents, such as CDOM, tripton and so on. Furthermore, according to the comparison with fluorescence peak, the authors also found that the reflectance peak intensity and the wavelength position of peak in red region are different from those of the fluorescence peak.