Carrier-free immobilized enzymatic reactor based on CipA-fused carbonyl reductase for efficient synthesis of chiral alcohol with cofactor self-sufficiency.

In this study, based on the self-assembly strategy, we fused CipA with carbonyl reductase LXCARS154Y derived from Leifsonia xyli by gene coding, and successfully performed the carrier-free immobilization of LXCARS154Y. The immobilized enzyme was then characterized using scanning electron microscope (SEM), dynamic light scattering (DLS) and fourier transform infrared spectroscopy (FTIR). Compared with the free enzyme, the immobilized LXCARS154Y exhibited a 2.3-fold improvement in the catalytic efficiency kcat/km for the synthesis of a chiral pharmaceutical intermediate (R)-3,5-bis(trifluoromethyl)phenyl ethanol ((R)-BTPE) by reducing 3,5-bis(trifluoromethyl)acetophenone (BTAP). Moreover, the immobilized enzyme showed the enhanced stability while maintaining over 61 % relative activity after 18 cycles of batch reaction. Further, when CipA-fused carbonyl reductase was employed for (R)-BTPE production in a continuous flow reaction, almost complete yield (97.0 %) was achieved within 7 h at 2 M (512.3 g/L) of BTAP concentration, with a space-time yield of 1717.1 g·L-1·d-1. Notably, we observed the retention of cofactor NADH by CipA-based enzyme aggregates, resulting in a higher total turnover number (TTN) of 4815 to facilitate this bioreductive process. This research developed a concise strategy for efficient preparation of chiral intermediate with cofactor self-sufficiency via continuous flow biocatalysis, and the relevant mechanism was also explored.

Disposable disinfection cap for preventing catheter-related blood stream infections: a Meta-analysis / 中国实用护理杂志

Objective:To evaluate the efficacy of disposable disinfection cap in preventing catheter-related blood stream infections (CRBSIs).Methods:Literature on the prevention of CRBSIs by disposable disinfection caps were retrieved from CNKI, Wanfang Database, VIP database, Chinese Biomedical Literature Database, PubMed, Cochrane Library, Embase and Web of Science databases. The retrieval period was from the database construction to June 30, 2022. After literature screening, data extraction and quality evaluation were independently carried out by 2 researchers, RevMan5.4 software was used for analysis.Results:A total of 12 articles were included, including 9 832 patients. Meta-analysis results showed that compared with conventional manual disinfection, disposable disinfection cap could reduce the incidence of CRBSIs, and the difference was statistically significant ( RR = 0.58, 95% CI 0.43-0.79, P<0.01). Disposable disinfection cap could reduce the incidence of CRBSIs in adults, but there was no significant difference in the incidence of CRBSIs in children ( P>0.05). It could reduce the incidence of CRBSIs in patients with indwelling vascular catheters in ICU ( RR = 0.58, 95% CI 0.38-0.89, P<0.05), but there was no statistical difference in the incidence of CRBSIs in patients without indwelling vascular catheters in ICU ( P>0.05). In addition, the compliance of the use of disinfection caps by nursing staff was improved by 80% - 90% and the treatment cost was saved by about 282 - 464 dollars. Conclusions:Disposable disinfection caps can reduce the occurrence of CRBSIs, improve the disinfection compliance of nursing staff, and save the hospitalization cost of patients. It is suggested to be popularized in clinical practice.

MetaDecoder: a novel method for clustering metagenomic contigs.

BACKGROUND: Clustering the metagenomic contigs into potential genomes is a key step to investigate the functional roles of microbial populations. Existing algorithms have achieved considerable success with simulated or real sequencing datasets. However, accurately classifying contigs from complex metagenomes is still a challenge. RESULTS: We introduced a novel clustering algorithm, MetaDecoder, which can classify metagenomic contigs based on the frequencies of k-mers and coverages. MetaDecoder was built as a two-layer model with the first layer being a GPU-based modified Dirichlet process Gaussian mixture model (DPGMM), which controls the weight of each DPGMM cluster to avoid over-segmentation by dynamically dissolving contigs in small clusters and reassigning them to the remaining clusters. The second layer comprises a semi-supervised k-mer frequency probabilistic model and a modified Gaussian mixture model for modeling the coverage based on single copy marker genes. Benchmarks on simulated and real-world datasets demonstrated that MetaDecoder can be served as a promising approach for effectively clustering metagenomic contigs. CONCLUSIONS: In conclusion, we developed the GPU-based MetaDecoder for effectively clustering metagenomic contigs and reconstructing microbial communities from microbial data. Applying MetaDecoder on both simulated and real-world datasets demonstrated that it could generate more complete clusters with lower contamination. Using MetaDecoder, we identified novel high-quality genomes and expanded the existing catalog of bacterial genomes. Video Abstract.

A bio-sensing surface with high biocompatibility for enhancing Raman scattering signals as enabled by a Mo-Ag film.

Biological surface-enhanced Raman scattering (SERS) sensing is dependent on the properties of the sensing surface. For the biological sensing surfaces for SERS, the hydrophilicity, biocompatibility and signal sensitivity are pivotal. Hence, a hard bimetallic Mo-Ag film was developed by a magnetron sputtering technique, and the surface morphology could be controlled by the relative contents of Mo and Ag. The Mo-Ag film has better hydrophilicity than the pure Ag film, which could be beneficial for cell attachment during biological SERS sensing. Moreover, the cell test shows that the Mo-Ag film exhibits good cytocompatibility with MC3T3-E1 cells, which shows potential for SERS detection in vivo. The high surface roughness of the Mo-Ag film is a fascinating feature for enhancing Raman scattering signals. Through depositing a thin film of Mo-Ag on a glass surface with a size of 0.5 × 0.5 cm2, a sensing chip of SERS could be produced. High sensitivity and excellent signal reproducibility were acquired. The sensitivity was down to 10-10 mol L-1 for malachite green and 10-9 mol L-1 for thiram, and the relative standard deviation value was lower than 7.0%. Moreover, bacteria were detected by employing the Mo-Ag film chip, and the difference in signal uniformity between molecules and bacteria is illustrated. In summary, depositing the Mo-Ag film on the surface of sensors could be an effective strategy for biomedical SERS sensing.

Modeling the complete spatiotemporal spread of the COVID-19 epidemic in mainland China.

OBJECTIVES: The novel coronavirus (COVID-19) epidemic is reaching its final phase in China. The epidemic data are available for a complete assessment of epidemiological parameters in all regions and time periods. METHODS: This study aims to present a spatiotemporal epidemic model based on spatially stratified heterogeneity (SSH) to simulate the epidemic spread. A susceptible-exposed/latent-infected-removed (SEIR) model was constructed for each SSH-identified stratum (each administrative city) to estimate the spatiotemporal epidemiological parameters of the outbreak. RESULTS: We estimated that the mean latent and removed periods were 5.40 and 2.13 days, respectively. There was an average of 1.72 latent or infected persons per 10,000 Wuhan travelers to other locations until January 20th, 2020. The space-time basic reproduction number (R0) estimates indicate an initial value between 2 and 3.5 in most cities on this date. The mean period for R0 estimates to decrease to 80%, and 50% of initial values in cities were an average of 14.73 and 19.62 days, respectively. CONCLUSIONS: Our model estimates the complete spatiotemporal epidemiological characteristics of the outbreak in a space-time domain. These findings will help enhance a comprehensive understanding of the outbreak and inform the strategies of prevention and control in other countries worldwide.

Ta@Ag Porous Array with High Stability and Biocompatibility for SERS Sensing of Bacteria.

The reliable sensing of bacteria by surface-enhanced Raman scattering (SERS) technology necessitates a rational design of a substrate with high sensitivity, stability, and minimal invasion. Hence, a bimetallic Ta@Ag film with a porous array is developed by the magnetron sputtering technique and the structure could be controlled by a Ta dopant. A porous array connected by ligaments with compact granular nanoprotrusions is a fascinating substrate for SERS sensing. It makes steady SERS signals even in harsh chemical environments due to its high structural and chemical stability. The configuration of binary Ta@Ag has higher surface free energy than that of pure Ag, and the strong bactericidal activity of Ag is suppressed efficiently. Using E. coli as a model pathogen, the Ta@Ag porous film could maintain the long-term survival rate of E. coli up to 95% and a limit of SERS detection of E. coli down to 102 CFU/mL, which is measured by the standard colony-counting method. In sum, this work provides a promising strategy to fabricate a corrosion-resistant and biocompatible bimetallic Ta@Ag film with a porous array for the SERS sensing of microbial cells.

Clinical features of 42 cases of COVID-19 / 上海预防医学

Objective To investigate the clinical features, laboratory findings, chest CT findings and treatment of patients with COVID-19, and to analyze their relationship with prognosis. Methods From January to February 2020, the clinical data on the 42 patients with COVID-19 admitted to the Wenzhou Sixth People′s Hospital were analyzed retrospectively. Results The clinical symptoms of the 42 cases included fever (35 cases), cough (26 cases), fatigue (14 cases), aspiration (9 cases), sore throat (4 cases), muscle ache (5 cases), headache (2 cases), nausea (4 cases), diarrhea (6 cases) and abdominal pain (1 case).The absolute number of blood lymphocyte decreased to different degrees in 22 cases.Fourteen cases had lactate dehydrogenase obviously, with no obvious change in procalcitonin.The imaging manifestations were cloud-like and ground-glass-like high density shadows scattered outside the lungs, small flaky consolidation and bronchus inflating sign were seen locally.A few images showed diffuse high density, most of the lesions showed consolidation or striate change, and local fibrosis was formed in the lower lobes of both lungs. Conclusion Fever and cough are the first symptoms of COVID-19, and a few cases are associated with shortness of breath and diarrhea, accompanied by different degrees of systemic symptoms, but most of the patients improve their conditions after active antivirus, anti-infection, systematic symptoms improvement and supportive treatment.The disease is highly infectious and its condition changes rapidly.Therefore, early detection, early diagnosis and comprehensive treatment of the whole body as soon as possible are the keys to treatment.

Star-Shaped Molecules as Dopant-Free Hole Transporting Materials for Efficient Perovskite Solar Cells: Multiscale Simulation.

On the reported TCP-OH (See Scheme 1), other two star-shaped molecules are theoretically designed by replacement of side group of TCP-OH by N,N-di(4-methoxyphenyl)aniline for TPAP-OH and oxygen-bridged triarylamine for TBOPP-OH. The core group, phenol, is kept in three molecules. Their potential to be hole transport material in perovskite solar cells without dopants is evaluated by multiscale simulations. The properties of isolated molecules are estimated by the frontier molecular orbital, absorption spectrum, and hole mobility. After that, the HTM@CH3 NH3 PbI3 adsorbed system is studied to consider the influence of adsorption on HTM performance. Besides the primary judgment, the glass transition temperature is also simulated to determine the stability of amorphous film. Not only the chemical stability is evaluated but also the amorphous film stability is considered. The latter is almost neglected in previous theoretical studies to evaluate the properties of HTMs. The performance of a designed molecule is evaluated from both the isolated molecules and HTM@CH3 NH3 PbI3 adsorbed system including aforementioned items, which is favorable to build reliable structure-property relationship.

Effects of five Chinese herbs on human demodicid mites in vitro / 中国血吸虫病防治杂志

Objective To research the effects of five Chinese herbs of Artemisia argyi, Chimonanthus praecox, Agastache rugosa, pine needles and Osmamthus fragrans on human demodicid mites in vitro. Methods The human demodicid mites were acquired with the cellophane tape method. The ethanol heat reflux extractions were carried out on the 5 kinds of Chinese herbs to be studied and Stemona sessilifolia as the positive control, so as to get the herbal extracts. Next, the drug administration was carried out to the demodicid mites, and the inhibitory or killing effects of the 6 kinds of Chinese herbs above mentioned on the vermiform mites were observed under a microscope. It was considered to be dead when the bodies of the demodicid mites stopped moving. Besides, the duration from drug administration to death of the vermiform mites was recorded. Results Artemisia argyi, Chimonanthus praecox and Agastache rugosa could effectively inhibit and kill human demodicid mites. The effect of Artemisia argyi and Agastache rugosa was similar to the effect of Stemona sessilifolia, and the effect of Chimonanthus praecox was weaker than Stemona sessilifolia’s effect. Among them, Agastache rugosa took a relatively short time (4.60 min ± 1.66 min) min and Osmamthus fragrans took the longest time (114.65min ± 80.14min) to Demodex folliculorum; Whereas, Artemisia argyi took the shortest time (3.56min ± 1.92 min) min and Osmamthus fragrans took the longest time (194.24min ± 134.96 min) min to Demodex brevis. Conclusions The effects of Artemisia argyi and Agastache rugosa on human demodicid mites are similar to that of Stemona sessilifolia. The effects of Chimonanthus praecox and pine needles are weaker than that of Stemona sessilifolia. Osmamthus fragrans has no acaricidal effect.

[Effects of five Chinese herbs on human demodicid mites in vitro].

OBJECTIVE: To research the effects of five Chinese herbs of Artemisia argyi, Chimonanthus praecox, Agastache rugosa, pine needles and Osmamthus fragrans on human demodicid mites in vitro. METHODS: The human demodicid mites were acquired with the cellophane tape method. The ethanol heat reflux extractions were carried out on the 5 kinds of Chinese herbs to be studied and Stemona sessilifolia as the positive control, so as to get the herbal extracts. Next, the drug administration was carried out to the demodicid mites, and the inhibitory or killing effects of the 6 kinds of Chinese herbs above mentioned on the vermiform mites were observed under a microscope. It was considered to be dead when the bodies of the demodicid mites stopped moving. Besides, the duration from drug administration to death of the vermiform mites was recorded. RESULTS: Artemisia argyi, Chimonanthus praecox and Agastache rugosa could effectively inhibit and kill human demodicid mites. The effect of Artemisia argyi and Agastache rugosa was similar to the effect of Stemona sessilifolia, and the effect of Chimonanthus praecox was weaker than Stemona sessilifolia's effect. Among them, Agastache rugosa took a relatively short time (4.60 min ± 1.66 min) min and Osmamthus fragrans took the longest time (114.65min ± 80.14min) to Demodex folliculorum; Whereas, Artemisia argyi took the shortest time (3.56min ± 1.92 min) min and Osmamthus fragrans took the longest time (194.24min ± 134.96 min) min to Demodex brevis. CONCLUSIONS: The effects of Artemisia argyi and Agastache rugosa on human demodicid mites are similar to that of Stemona sessilifolia. The effects of Chimonanthus praecox and pine needles are weaker than that of Stemona sessilifolia. Osmamthus fragrans has no acaricidal effect.