Enhanced production of aspochalasin D through genetic engineering of Aspergillus flavipes.

Aspochalasin D (AD) belongs to the polyketide-amino acid hybrid natural products with anti-cancer, anti-bacterial, and anti-fouling bioactivities. However, the low production limits its further application. In this study, AD was separated and identified from Aspergillus flavipes 3.17641. Next, besides the optimization of culture conditions using a single-factor experiment and response surface methodology, metabolic engineering was employed to increase the AD production. It shows that the deletion of the shunt gene aspoA and overexpression of the pathway-specific regulator aspoG significantly improve the AD production. Its production reached to 812.1 mg/L under the optimized conditions, with 18.5-fold increase. Therefore, this study not only provides a general method for improving the production of similar natural products in other fungi, but also enables the further biological function development of AD in agriculture and pharmaceutical. KEY POINTS: • The Aspochalasin D (AD) production was improved by optimizing culture conditions. • The deletion of the shunt gene aspoA increased the AD production. • Overexpression of the pathway regulator aspoG further improved the AD production.

SwinOCSR: end-to-end optical chemical structure recognition using a Swin Transformer.

Optical chemical structure recognition from scientific publications is essential for rediscovering a chemical structure. It is an extremely challenging problem, and current rule-based and deep-learning methods cannot achieve satisfactory recognition rates. Herein, we propose SwinOCSR, an end-to-end model based on a Swin Transformer. This model uses the Swin Transformer as the backbone to extract image features and introduces Transformer models to convert chemical information from publications into DeepSMILES. A novel chemical structure dataset was constructed to train and verify our method. Our proposed Swin Transformer-based model was extensively tested against the backbone of existing publicly available deep learning methods. The experimental results show that our model significantly outperforms the compared methods, demonstrating the model's effectiveness. Moreover, we used a focal loss to address the token imbalance problem in the text representation of the chemical structure diagram, and our model achieved an accuracy of 98.58%.

Development of the general chapters of the Chinese Pharmacopoeia 2020 edition: A review.

The Chinese Pharmacopoeia 2020 edition was reviewed and approved by the National Medical Products Administration and the National Health Commission of the People's Republic of China in July 2020. The current edition was officially implemented on December 30, 2020. The general chapters of the Chinese Pharmacopoeia discuss the general testing methods and guidelines, which are the common requirements and basis for the implementation of drug standards in the Chinese Pharmacopoeia. Owing to adherence to the principles of scientificity, versatility, operability, and sustainable development, there is an improvement in the general chapters of the 2020 edition over those of the previous editions. Further, the application of advanced and mature analytical techniques has expanded, the development of testing methods for exogenous pollutants in traditional Chinese medicines has been strengthened, and technical requirements are now better harmonized with international standards. The updated edition provides technical and methodological support to ensure safety, effectiveness, and control of pharmaceuticals in China and will play an important and active role in encouraging the application of advanced technologies, improving the quality control of medicines, and strengthening the means of drug regulation in China. This review provides a comprehensive introduction of the main features of and changes to the general chapters in the Chinese Pharmacopoeia 2020 edition and aims to provide reference for its correct understanding and accurate implementation.

Development of the general chapters of the Chinese Pharmacopoeia 2020 edition:A review / 药物分析学报

The Chinese Pharmacopoeia 2020 edition was reviewed and approved by the National Medical Products Administration and the National Health Commission of the People's Republic of China in July 2020.The current edition was officially implemented on December 30,2020.The general chapters of the Chinese Pharmacopoeia discuss the general testing methods and guidelines,which are the common re-quirements and basis for the implementation of drug standards in the Chinese Pharmacopoeia.Owing to adherence to the principles of scientificity,versatility,operability,and sustainable development,there is an improvement in the general chapters of the 2020 edition over those of the previous editions.Further,the application of advanced and mature analytical techniques has expanded,the development of testing methods for exogenous pollutants in traditional Chinese medicines has been strengthened,and technical requirements are now better harmonized with international standards.The updated edition provides technical and methodological support to ensure safety,effectiveness,and control of pharmaceuticals in China and will play an important and active role in encouraging the application of advanced technolo-gies,improving the quality control of medicines,and strengthening the means of drug regulation in China.This review provides a comprehensive introduction of the main features of and changes to the general chapters in the Chinese Pharmacopoeia 2020 edition and aims to provide reference for its correct understanding and accurate implementation.

Aquatic ecotoxicity of an antidepressant, sertraline hydrochloride, on microbial communities.

Sertraline hydrochloride (Ser-HCl), a widely used antidepressant, becomes an aquatic contaminant via metabolic excretion and improper disposal; however, it is unknown how Ser-HCl affects aquatic microbial communities. The present study investigated the effects of Ser on the structures of aquatic microbial communities via high-throughput sequencing analyses. Ser-HCl treatment inhibited the growth of two model algae (the green alga, Chlorella vulgaris, and the cyanobacterium, Microcystis aeruginosa) and decreased the chlorophyll a (Chl-a) concentration in the microcosm to reduce the photosynthetic efficiency. High-throughput sequencing analyses showed that exposure to Ser-HCl disturbed the balance of cyanobacteria species by stimulating the growth of specific cyanobacteria. Among eukaryotes, the richness as well as the diversity indices were significantly enhanced after 5 days of Ser-HCl treatment but sharply decreased with exposure time. Nucleariida occupied an absolute majority (97.83%) within the eukaryotes, implicating that Ser-HCl disturbed the ecological equilibrium in microcosms. Ser-HCl will continue to be an environmental contaminant due to its wide usage and production. Our current study clarified the potential ecological risk of Ser-HCl to aquatic microorganisms. These findings suggest that more attention should be given to the negative effects of these bioactive pollutants on aquatic environments.

[Single-use Medical Devices Re-processing: Risk Assessment and Quality Control Technologies].

The reuse of high-cost single-use medical devices (SUD) is permitted in many countries, such as the United States, Germany and the United Kingdom, but strict regulatory requirements must be met. In addition to regulatory policies and regulations, such as market access mode and special requirements on Good Manufacture Practice (GMP), there are strict technical requirements on the potential risk control and quality assurance system. Therefore, effective risk assessment and risk control technology are the keys to ensure effective quality control and safe use of SUDs. In this article, based on analyzing the technological requirements of the national regulatory on SUDs in the United States, Germany and Britain, and combined with the review from latest relevant literature, to discuss the strategies of how to carry out scientific risk assessment. Some risk control technologies on the reuse of SUDs are introduced, which will provide support for the further study on risk control strategies and regulatory decisions for the reuse of SUDs in China.

[Cell Count of Mouse Blastocyst on Pre-clinical Evaluation of Safety of Medical Devices in Assisted Reproductive Technologies].

Various types of medical devices used in assisted reproductive technologies (ART) should be detected for their safety by strict biological assays. Mouse embryo assay(MEA)has been recognized as one of the most important and standardized methods with the threshold more than 80% of blastocyst formation rate (BR) after 96 h culture of fertilized eggs. The disadvantage using BR for embryonic quality control has been concerned as it is ubiquitously dependent of embryonic morphology and the detailed data including molecular and genetic information is obviously missing and incomplete. This leads to the urgent requirement for more sensitive and efficient assessments for the quality control of ART. This study evaluated the reliability of an immunofluorescent MEA by counting total cell and differential number of the cells in the inner cell mass (ICM) and trophectoderm (TE) in the blastocyst. This method improved the traditional MEA, provided a sensitive and powerful platform to assess embryonic developmental viability and should be suggested as a standard assay to be globally used for the quality control of medical devices and pre-clinical procedures in ART.

Responses of unicellular alga Chlorella pyrenoidosa to allelochemical linoleic acid.

Linoleic acid (LA), is the product of secondary metabolism secreted from Microcystis aeruginosa, and it exhibits allelopathic activity against eukaryotic algae. However, information about on the mechanisms associated with the inhibition of algal activity by LA is limited. In this study, Chlorella pyrenoidosa was treated with LA (20-120 µg L-1) for 4 days, and its growth inhibition and physiological responses were examined for potential toxic mechanisms. The photosynthetic efficiency of C. pyrenoidosa was inhibited by LA treatments, and the Fv/Fm parameter decreased significantly compared to that of controls; however, the photosynthetic pigment content did not change significantly. Peroxidase activity was enhanced, relieving oxidative damage in algae after LA treatments. However, superoxide dismutase and catalase were suppressed, ultimately leading to the aggravation of lipid peroxidation. Transcriptome-based gene expression analysis revealed that the 120 µg L-1 LA treatment significantly inhibited the transcription of genes related to photosynthesis, carbon metabolism, and amino acid metabolism in C. pyrenoidosa, suggesting that these genes might be key LA targets in C. pyrenoidosa. Moreover, the expression of genes involved in vitamin, lipid, nitrogen cycling, terpenoid, and ascorbate metabolism was also affected, suggesting that LA inhibits algal cell growth through multiple pathways. The identification of LA-responsive genes in C. pyrenoidosa provides new insight into LA stress responses in eukaryotic algae.

[Single-use Medical Devices Re-processing: Regulatory Status Quo].

Some single-use medical devices are reprocessed and reused in some countries in the world, but the regulatory approach is different, and in some countries it isn't regulated yet. In this article, the regulatory status quo of single-use medical devices is reviewed. The regulatory development, important regulatory documents and regulatory approaches of single-use medical device reprocessing in the United States, Germany and the UK are introduced. And how to perform scientific risk assessment and effective risk control is discussed. The information is useful to establish China-specific regulations, and to develop relevant standards, guidelines or specifications and the risk control strategies.

A reference human genome dataset of the BGISEQ-500 sequencer.

Background: BGISEQ-500 is a new desktop sequencer developed by BGI. Using DNA nanoball and combinational probe anchor synthesis developed from Complete Genomics™ sequencing technologies, it generates short reads at a large scale. Here, we present the first human whole-genome sequencing dataset of BGISEQ-500. The dataset was generated by sequencing the widely used cell line HG001 (NA12878) in two sequencing runs of paired-end 50 bp (PE50) and two sequencing runs of paired-end 100 bp (PE100). We also include examples of the raw images from the sequencer for reference. Finally, we identified variations using this dataset, estimated the accuracy of the variations, and compared to that of the variations identified from similar amounts of publicly available HiSeq2500 data. We found similar single nucleotide polymorphism (SNP) detection accuracy for the BGISEQ-500 PE100 data (false positive rate [FPR] = 0.00020%, sensitivity = 96.20%) compared to the PE150 HiSeq2500 data (FPR = 0.00017%, sensitivity = 96.60%) better SNP detection accuracy than the PE50 data (FPR = 0.0006%, sensitivity = 94.15%). But for insertions and deletions (indels), we found lower accuracy for BGISEQ-500 data (FPR = 0.00069% and 0.00067% for PE100 and PE50 respectively, sensitivity = 88.52% and 70.93%) than the HiSeq2500 data (FPR = 0.00032%, sensitivity = 96.28%). Our dataset can serve as the reference dataset, providing basic information not just for future development, but also for all research and applications based on the new sequencing platform.

Premarket Regulation of Tissue Engineered Medical Products in China.

Tissue engineered medical products (TEMPs) use state-of-the-art technologies and offer the patients with alternative clinical options for diseases that conventional treatments may fail or be incompetent. However promising, this technology is comparatively new with very limited hands-on experiences with both manufacturing and clinical therapy. Of great significance to products with such complexity and novelty is the establishment of a complete jurisdiction framework and a standardization database so that the safety of the technique in clinical treatment can be ensured. Although different regulatory routes are adopted in different countries, risks are generally considered to be derived from the cellular components within the product, the material scaffolds, and potentially from the final products. This article is to provide an insight of the regulatory considerations and the role of China Food and Drug Administration (CFDA) in the supervision of TEMPs.

[Analysis of the National Quality Inspection for Medical Devices].

This paper analyses overall situation of the national quality inspection for medical devices in recent 13 years. The statistics cover the inspected varieties, sampling quantity and quality status. The achievements and suggestions are provided, which are helpful for future work.

One-Step Reverse-Transcription FRET-PCR for Differential Detection of Five Ebolavirus Species.

Ebola is an emerging infectious disease caused by a deadly virus belonging to the family Filoviridae, genus Ebolavirus. Based on their geographical distribution, Ebolavirus has been classified into total five species so far, mainly Zaire, Sudan, Taï Forest, Bundibugyo and Reston. It is important to be able to differentiate the Ebolavirus species as they significantly differ in pathogenicity and more than one species can be present in an area. We have developed a one-step step-down RT-PCR detecting all five Ebolavirus species with high sensitivity (1 copy of Ebolavirus DNA, 10 copies of RNA and 320 copies of RNA spiked in 1 ml whole blood). The primers and FRET-probes we designed enabled us to differentiate five Ebolavirus species by distinct Tm (Zaire: flat peaks between 53.0°C and 56.9°C; Sudan: 51.6°C; Reston: flat peaks between 47.5°C and 54.9°C; Tai Forest: 52.8°C; Bundibugyo: dual peaks at 48.9°C and 53.5°C), and by different amplicon sizes (Zaire 255 bp, Sudan 211 bp, Reston 192 bp, Taï Forest 166 bp, Bundibugyo 146 bp). This one-size-fit-all assay enables the rapid detection and discrimination of the five Ebolavirus species in a single reaction.

Tissue toxicity following the vaginal administration of nanosilver particles in rabbits.

Nanosilver particles are used in various clinical settings because of their antibacterial properties. However, their safety evaluation when used for gynaecological disorders has not been established. Nanosilver particles were administrated in the vagina of New Zealand rabbits, and the pathological appearance of the surrounding tissue was examined by hematoxylin-eosin staining and transmission electron microscopy (TEM) after 1 and 3 days of treatment. The nanosilver content was assessed by plasma mass spectrometry, and the presence of particles in the hepatic portal vein blood was assessed by TEM. The results of our study show that the vaginal administration of nanosilver particles caused ultrastructural changes to the vaginal mucosa, urethra and rectum, with accumulation of particles in all tissues. These results demonstrate a new migration route of nanosilver particles following vaginal administration. They also demonstrate, for the first time, that the vaginal administration of nanosilver particles can enter the blood circulation system by examining the hepatic portal vein blood under the TEM which is the most direct visualized evidence.

[Situation and suggestions on IVD industrial standards].

This paper briefly introduces the working procedure of in vitro diagnostic products (IVD) industrial standards, and elaborates the importance of professional standards for production and supervision. Based on the analysis of working progress during the past 10 years, some problems and countermeasures on project setting, participation, standard material, personnel training, work cycle are put forward, which are helpful for the future development of the IVD.

[Comments and suggestions on the medical device standardization system from the view point of medical devices test].

Medical device test is a very important step of medical device registration processes and is also a procedure to confirm whether the medical devices comply with applicable standards. The standardization system is imperfect yet in China due to the complexity of medical devices and the specialty of medical device industry. In this circumstance, the medical device standard is not only the important criteria for the medical devices registration, but also an important practical procedure of the medical device registration. This paper reviews the existing questions and also gives some comments and suggestions on the medical device standardization system from the view point of medical device test.

[The preparation and bioactivity assessment of gene recombinant fibrin-binding brain derived neurotrophic factor].

Using the E. coli, we fabricated the gene reconstructed brain derived neurotrophic factor with a fibrin binding domain (FBD-BDNF). We then tested the neurotrophic bioactivity and fibrin-binding ability of the FBD-BDNF. The E. coli was used to express the recombinant protein. The inclusion body was purified with column chromatography and renaturated to construct the right 3D formation. In this study, we successfully fabricated the FBD-BDNF and tested the binding ability and neurotrophic activity. The results demonstrated that FBD-BDNF had special binding ability of fibrin and significant neurotrophic activity for DRG cells. FBD-BDNF could have a promising application prospect in nerve tissue engineering.