Elucidation of the Biosynthesis of Griseoluteic Acid in Streptomyces griseoluteus P510.

Phenazines are aromatic compounds with antifungal and cytotoxic activities. Phenazines incorporating phenazine 1-carboxylic acid have widespread applications in agriculture, medicine, and industry. Griseoluteic acid is a cytotoxic compound secreted by Streptomyces griseoluteus P510, displaying potential medical applications. However, the biosynthetic pathway of griseoluteic acid has not been elucidated, limiting its development and application. In this study, a conserved phenazine biosynthetic gene cluster of S. griseoluteus P510 was identified through genomic analysis. Subsequently, its was confirmed that the four essential modification enzymes SgpH, SgpI, SgpK, and SgpL convert phenazine-1,6-dicarboxylic acid into griseoluteic acid by heterologous expression in Escherichia coli. Moreover, the biosynthetic pathway of griseoluteic acid was established in Pseudomonas chlororaphis characterized by a high growth rate and synthesis efficiency of phenazines, laying the foundation for the efficient production of griseoluteic acid.

Development of Stable Water-Soluble Supratomic Silver Clusters Utilizing A Polyoxoniobate-Protected Strategy: Giant Core-Shell-Type Ag8@Nb162 Fluorescent Nanocluster.

Atomically precise low-nuclearity (n<10) silver nanoclusters (AgNCs) have garnered significant interest due to their size-dependent optical properties and diverse applications. However, their synthesis has remained challenging, primarily due to their inherent instability. The present study introduces a new feasible approach for clustering silver ions utilizing highly negative and redox-inert polyoxoniobates (PONbs) as all-inorganic ligands. This strategy not only enables the creation of novel Ag-PONb composite nanoclusters but also facilitates the synthesis of stable low-nuclearity AgNCs. Using this method, we have successfully synthesized a small octanuclear rhombic [Ag8]6+ AgNC stabilized by six highly negative [LiNb27O75]14- polyoxoanions. This marks the first PONb-protected superatomic AgNC, designated as {Ag8@(LiNb27O75)6} (Ag8@Nb162), with an aesthetically spherical core-shell structure. The crystalline Ag8@Nb162 is stable under ambient conditions, What's more, it is water-soluble and able to maintain its molecular cluster structure intact in water. Further, the stable small [Ag8]6+ AgNC has interesting temperature- and pH-dependent reversible fluorescence response, based on which a multiple optical encryption mode for anti-counterfeit technology was demonstrated. This work offers a promising avenue for the synthesis of fascinating and stable PONb-protected AgNCs and sheds light on the development of new-type optical functional materials.

Hippocampal proteome comparison of infant and adult Fmr1 deficiency mice reveals adult-related changes associated with postsynaptic density.

Deficiency in fragile X mental retardation 1 (Fmr1) leads to loss of its encoded protein FMRP and causes fragile X syndrome (FXS) by dysregulating its target gene expression in an age-related fashion. Using comparative proteomic analysis, this study identified 105 differentially expressed proteins (DEPs) in the hippocampus of postnatal day 7 (P7) Fmr1-/y mice and 306 DEPs of P90 Fmr1-/y mice. We found that most DEPs in P90 hippocampus were not changed in P7 hippocampus upon FMRP absence, and some P90 DEPs exhibited diverse proteophenotypes with abnormal expression of protein isoform or allele variants. Bioinformatic analyses showed that the P7 DEPs were mainly enriched in fatty acid metabolism and oxidoreductase activity and nutrient responses; whereas the P90 PEPs (especially down-regulated DEPs) were primarily enriched in postsynaptic density (PSD), neuronal projection development and synaptic plasticity. Interestingly, 25 of 30 down-regulated PSD proteins present in the most enriched protein to protein interaction network, and 6 of them (ANK3, ATP2B2, DST, GRIN1, SHANK2 and SYNGAP1) are both FMRP targets and autism candidates. Therefore, this study suggests age-dependent alterations in hippocampal proteomes upon loss of FMRP that may be associated with the pathogenesis of FXS and its related disorders. SIGNIFICANCE: It is well known that loss of FMRP resulted from Fmr1 deficiency leads to fragile X syndrome (FXS), a common neurodevelopmental disorder accompanied by intellectual disability and autism spectrum disorder (ASD). FMRP exhibits distinctly spatiotemporal patterns in the hippocampus between early development and adulthood, which lead to distinct dysregulations of gene expression upon loss of FMRP at the two age stages potentially linked to age-related phenotypes. Therefore, comparison of hippocampal proteomes between infancy and adulthood is valuable to provide insights into the early causations and adult-dependent consequences for FXS and ASD. Using a comparative proteomic analysis, this study identified 105 and 306 differentially expressed proteins (DEPs) in the hippocampi of postnatal day 7 (P7) and P90 Fmr1-/y mice, respectively. Few overlapping DEPs were identified between P7 and P90 stages, and the P7 DEPs were mainly enriched in the regulation of fatty acid metabolism and oxidoreduction, whereas the P90 DEPs were preferentially enriched in the regulation of synaptic formation and plasticity. Particularly, the up-regulated P90 proteins are primarily involved in immune responses and neurodegeneration, and the down-regulated P90 proteins are associated with postsynaptic density, neuron projection and synaptic plasticity. Our findings suggest that distinctly changed proteins in FMRP-absence hippocampus between infancy and adulthood may contribute to age-dependent pathogenesis of FXS and ASD.

Dynamic immobilization of bacterial cells on biofilm in a polyester nonwoven chemostat.

Cell immobilization plays an important role in biocatalysis for high-value products. It is necessary to maintain the viability of immobilized cells for bioconversion using viable cells as biocatalysts. In this study, a novel polyester nonwoven chemostat was designed for cell immobilization to investigate biofilm formation and the dynamic balance between adsorption and desorption of cells on polyester nonwoven. The polyester nonwoven was suitable for cell immobilization, and the cell numbers on the polyester nonwoven can reach 6.5 ± 0.38 log CFU/mL. After adding the polyester nonwoven to the chemostat, the fluctuation phenomenon of free bacterial cells occurred. The reason for this phenomenon was the balance between adsorption and desorption of bacterial cells on the polyester nonwoven. Bacterial cells could adhere to the surface of polyester nonwoven via secreting extracellular polymeric substances (EPS) to form biofilms. As the maturation of biofilms, some dead cells inside the biofilms can cause the detachment of biofilms. This process of continuous adsorption and desorption of cells can ensure that the polyester nonwoven chemostat has lasting biological activity.

Artificial nonenzymatic antioxidant Prussian blue/KGM-BSA nanocomposite hydrogel dressing as ROS scavenging for diabetic wound healing.

The process of diabetic wound healing was influenced by the excessive proliferation of reactive oxygen species (ROS). Therefore, in the process of healing diabetic wounds, it was crucial to removing ROS. This study designed composited nanoparticles: KBP, consisted by Konjac glucomannan, bovine serum albumin, and Prussian blue. Then they were embedded in Konjac glucomannan and hydroxypropyl trimethylammonium chloride chitosan composite hydrogel (KH), The KBP@KH hydrogel finally achieved excellent efficacy in diabetic wound healing. The in vitro and in vivo experiments demonstrated that KPB nanoparticles exhibited favorable ROS scavenging capability and biosafety. The KBP@KH hydrogel not only effectively eliminated ROS from diabetic wounds, but also exhibited excellent wound adaptability. The KBP@KH hydrogel facilitated angiogenesis and suppressed the production of inflammatory factors. Overall, the KBP@KH hydrogel dressing was characterized by its user-friendly nature, safety, and high efficiency.

Development of the Static and Dynamic Gene Expression Regulation Toolkit in Pseudomonas chlororaphis.

The advancement of metabolic engineering and synthetic biology has promoted in-depth research on the nonmodel microbial metabolism, and the potential of nonmodel organisms in industrial biotechnology is becoming increasingly evident. The nonmodel organism Pseudomonas chlororaphis is a safe plant growth promoting bacterium for the production of phenazine compounds; however, its application is seriously hindered due to the lack of an effective gene expression precise regulation toolkit. In this study, we constructed a library of 108 promoter-5'-UTR (PUTR) and characterized them through fluorescent protein detection. Then, 6 PUTRs with stable low, intermediate, and high intensities were further characterized by report genes lacZ encoding ß-galactosidase from Escherichia coli K12 and phzO encoding PCA monooxygenase from P. chlororaphis GP72 and thus developed as a static gene expression regulation system. Furthermore, the stable and high-intensity expressed PMOK_RS0128085UTR was fused with the LacO operator to construct an IPTG-induced plasmid, and a self-induced plasmid was constructed employing the high-intensity PMOK_RS0116635UTR regulated by cell density, resulting in a dynamic gene expression regulation system. In summary, this study established two sets of static and dynamic regulatory systems for P. chlororaphis, providing an effective toolkit for fine-tuning gene expression and reprograming the metabolism flux.

Dynamic Acoustic Beamshaping with Coupling-Immune Moiré Metasurfaces.

Moiré effects arising from mutually twisted metasurfaces have showcased remarkable wave manipulation capabilities, unveiling tantalizing emerging phenomena such as acoustic moiré flat bands and topological phase transitions. However, the pursuit of strong near-field coupling in layers has necessitated acoustic moiré metasurfaces to be tightly stacked at narrow distances in the subwavelength range. Here, moiré effects beyond near-field interlayer coupling in acoustics are reported and the concept of coupling-immune moiré metasurfaces is proposed. Remote acoustic moiré effects decoupled from the interlayer distance are theoretically, numerically, and experimentally demonstrated. Tunable out-of-plane acoustic beam scanning is successfully achieved by dynamically controlling twist angles. The engineered coupling-immune properties are further extended to multilayered acoustic moiré metasurfaces and manipulation of acoustic vortices. Good robustness against external disturbances is also observed for the fabricated coupling-immune acoustic moiré metasurfaces. The presented work unlocks the potential of twisted moiré devices for out-of-plane acoustic beam shaping, enabling practical applications in remote dynamic detection, and multiplexed underwater acoustic communication.

G-site residue S67 is involved in the fungicide-degrading activity of a tau class glutathione S-transferase from Carica papaya.

Thiram is a toxic fungicide extensively used for the management of pathogens in fruits. Although it is known that thiram degrades in plant tissues, the key enzymes involved in this process remain unexplored. In this study, we report that a tau class glutathione S-transferase (GST) from Carica papaya can degrade thiram. This enzyme was easily obtained by heterologous expression in Escherichia coli, showed low promiscuity toward other thiuram disulfides, and catalyzed thiram degradation under physiological reaction conditions. Site-directed mutagenesis indicated that G-site residue S67 shows a key influence for the enzymatic activity toward thiram, while mutation of residue S13, which reduced the GSH oxidase activity, did not significantly affect the thiram-degrading activity. The formation of dimethyl dithiocarbamate, which was subsequently converted into carbon disulfide, and dimethyl dithiocarbamoylsulfenic acid as the thiram degradation products suggested that thiram undergoes an alkaline hydrolysis that involves the rupture of the disulfide bond. Application of the GST selective inhibitor 4-chloro-7-nitro-2,1,3-benzoxadiazole reduced papaya peel thiram-degrading activity by 95%, indicating that this is the main degradation route of thiram in papaya. GST from Carica papaya also catalyzed the degradation of the fungicides chlorothalonil and thiabendazole, with residue S67 showing again a key influence for the enzymatic activity. These results fill an important knowledge gap in understanding the catalytic promiscuity of plant GSTs and reveal new insights into the fate and degradation products of thiram in fruits.

Management of deep sacral and ischial pressure injuries with free-style local perforator flaps: A D+P+DPD model.

BACKGROUND: Previous reports on the treatment of sacral and ischial pressure injuries have not provided clear algorithms for surgical therapies. The objective of this study was to establish a reconstruction algorithm to guide the selection of an ideal free-style perforator flap that can be tailored to the defect in question. METHODS: We used 23 perforator flaps to reconstruct 14 sacral and 8 ischial defects in 22 patients over 5 years. A reconstruction algorithm system was developed based on the anatomical features of the perforator vessels (diameter, D; pulsatility [++∼+++], P) and their position in the skin island (DPD) (ie, D+P+DPD). A perforator-based propeller flap was applied as the first-line choice; if this plan was not feasible, we applied an altered V-Y advancement model or another second-choice technique. RESULTS: All flaps survived, and only 1 patient experienced partial wound dehiscence, which healed by secondary intention. After an average follow-up period of 11.2 months, no patient experienced recurrence or infection. CONCLUSIONS: Free-style perforator flap selection is determined by pressure injury and the desired advantage of a specific approach. The use of free-style perforator-based propeller flaps allows a surgeon to transfer healthy tissue into the defect, shifts the suture line away from the bony prominence, and preserves additional future donor sites. In cases where unexpected variations are encountered, the V-Y advancement model or another technique can be used. The simplified surgical algorithm (D+P+DPD) can provide versatility and reliability, achieve a durable, natural esthetic outcome, and minimize injuries to future donor sites.

Engineering protein translocation and unfolded protein response enhanced human PH-20 secretion in Pichia pastoris.

Hyaluronidases catalyze the degradation of hyaluronan (HA), which is finding rising applications in medicine, cosmetic, and food industries. Recombinant expression of hyaluronidases in microbial hosts has been given special attention as a sustainable way to substitute animal tissue-derived hyaluronidases. In this study, we focused on optimizing the secretion of hyaluronidase from Homo sapiens in Pichia pastoris by secretion pathway engineering. The recombinant hyaluronidase was first expressed under the control of a constitutive promoter PGCW14. Then, two endoplasmic reticulum-related secretory pathways were engineered to improve the secretion capability of the recombinant strain. Signal peptide optimization suggested redirecting the protein into co-translational translocation using the ost1-proα signal sequence improved the secretion level by 20%. Enhancing the co-translational translocation by overexpressing signal recognition particle components further enhanced the secretory capability by 48%. Then, activating the unfolded protein response by overexpressing a transcriptional factor ScHac1p led to a secreted hyaluronidase activity of 4.06 U/mL, which was 2.1-fold higher than the original strain. Finally, fed-batch fermentation elevated the production to 19.82 U/mL. The combined engineering strategy described here could be applied to enhance the secretion capability of other proteins in yeast hosts. KEY POINTS: • Improving protein secretion by enhancing co-translational translocation in P. pastoris was reported for the first time. • Overexpressing Hac1p homologous from different origins improved the rhPH-20 secretion. • A 4.9-fold increase in rhPH-20 secretion was achieved after fermentation optimization and fed-batch fermentation.

[Risk factors for delayed bleeding after intestinal polypectomy in children]. / å„¿ç«¥è‚ æ¯è‚‰åˆ‡é™¤æœ¯åŽè¿Ÿå‘æ€§å‡ºè¡€çš„å±é™©å› ç´ åˆ†æž.

OBJECTIVES: To investigate the clinical characteristics and risk factors of delayed bleeding after intestinal polypectomy in children, and to provide a theoretical basis for clinical surgical intervention of intestinal polyps. METHODS: A retrospective analysis was conducted on the clinical data of 2 456 children with intestinal polyps who underwent endoscopic high-frequency electrocoagulation loop resection in the Endoscopy Center of Children's Hospital Affiliated to Zhengzhou University from January 2014 to December 2021. According to the presence or absence of delayed bleeding after surgery, they were divided into bleeding group with 79 children and non-bleeding group with 2 377 children. A multivariate logistic regression analysis was used to investigate the risk factors for delayed bleeding. The receiver operating characteristic (ROC) curve was used to investigate the value of various indicators in predicting delayed bleeding. RESULTS: Of all 2 456 children, 79 (3.22%) experienced delayed bleeding, among whom 5 children with severe delayed bleeding underwent emergency colonoscopy for hemostasis and 74 received conservative treatment, and successful hemostasis was achieved for all children. There were significant differences between the bleeding and non-bleeding groups in age, body mass index, constipation rate, location of lesion, time of endoscopic procedure, resection method (P<0.05). Children with a diameter of polyps of 6-10 mm and >20 mm were more likely to develop delayed bleeding after resection (P<0.05). The multivariate logistic regression analysis showed that endoscopic operation time, polyp diameter, and resection method were significantly associated with delayed bleeding (P<0.05). The ROC curve analysis showed that the endoscopic operation time, polyp diameter, and resection method had a good value in predicting delayed bleeding after intestinal polypectomy, with an area under the ROC curve of 0.706, 0.688, and 0.627, respectively. CONCLUSIONS: Endoscopic high-frequency electrocoagulation loop resection has a lower incidence of delayed bleeding in children with intestinal polyps, and the endoscopic operation time, polyp diameter, and resection method are closely associated with the occurrence of postoperative delayed bleeding.

Risk factors for delayed bleeding after intestinal polypectomy in children / 中国当代儿科杂志

OBJECTIVES@#To investigate the clinical characteristics and risk factors of delayed bleeding after intestinal polypectomy in children, and to provide a theoretical basis for clinical surgical intervention of intestinal polyps.@*METHODS@#A retrospective analysis was conducted on the clinical data of 2 456 children with intestinal polyps who underwent endoscopic high-frequency electrocoagulation loop resection in the Endoscopy Center of Children's Hospital Affiliated to Zhengzhou University from January 2014 to December 2021. According to the presence or absence of delayed bleeding after surgery, they were divided into bleeding group with 79 children and non-bleeding group with 2 377 children. A multivariate logistic regression analysis was used to investigate the risk factors for delayed bleeding. The receiver operating characteristic (ROC) curve was used to investigate the value of various indicators in predicting delayed bleeding.@*RESULTS@#Of all 2 456 children, 79 (3.22%) experienced delayed bleeding, among whom 5 children with severe delayed bleeding underwent emergency colonoscopy for hemostasis and 74 received conservative treatment, and successful hemostasis was achieved for all children. There were significant differences between the bleeding and non-bleeding groups in age, body mass index, constipation rate, location of lesion, time of endoscopic procedure, resection method (P<0.05). Children with a diameter of polyps of 6-10 mm and >20 mm were more likely to develop delayed bleeding after resection (P<0.05). The multivariate logistic regression analysis showed that endoscopic operation time, polyp diameter, and resection method were significantly associated with delayed bleeding (P<0.05). The ROC curve analysis showed that the endoscopic operation time, polyp diameter, and resection method had a good value in predicting delayed bleeding after intestinal polypectomy, with an area under the ROC curve of 0.706, 0.688, and 0.627, respectively.@*CONCLUSIONS@#Endoscopic high-frequency electrocoagulation loop resection has a lower incidence of delayed bleeding in children with intestinal polyps, and the endoscopic operation time, polyp diameter, and resection method are closely associated with the occurrence of postoperative delayed bleeding.

Hippocampal proteomic changes in high-fat diet-induced obese mice associated with memory decline.

Substantial evidence suggest that chronic consumption of high-fat diets (HFDs) can lead to obesity, abnormal metabolism, as well as cognitive impairment. Molecular and cellular changes regarding hippocampal dysfunctions have been identified in multiple HFD animal models. Therefore, in-depth identification of expression changes of hippocampal proteins is critical for understanding the mechanism of HFD-induced cognitive deficits. In this study, we fed 3-week-old male mice with HFD for 3 months to generate obese mice who exhibit systemic metabolic abnormality and learning and memory decline. Using an iTRAQ-labeled proteomic analysis, we identified a total of 82 differentially expressed proteins (DEPs) in the hippocampus upon HFD with 35 up-regulated proteins and 47 down-regulated proteins. Functional enrichment indicated that these DEPs were predominantly enriched in regulation of catabolic process, dendritic shaft, neuron projection morphogenesis and GTPase regulator activity. Protein-protein interaction enrichment showed that the DEPs are mostly enriched in postsynaptic functions; and of them, six proteins (i.e., DLG3, SYNGAP1, DCLK1, GRIA4, GRIP1, and ARHGAP32) were involved in several functional assemblies of the postsynaptic density including G-protein signaling, scaffolding and adaptor, kinase and AMPA signaling, respectively. Collectively, our findings suggest that these DEPs upon HFD might contribute to memory decline by disturbing neuronal and postsynaptic functions in the hippocampus.

Excellent Dark/Light Dual-Mode Photoresponsive Activities Based on g-C3N4/CMCh/PVA Nanocomposite Hydrogel Using Electron Beam Radiation Method.

Photocatalytic technology for inactivating bacteria in water has received much attention. In this study, we reported a dark-light dual-mode sterilized g-C3N4/chitosan/poly (vinyl alcohol) hydrogel (g-CP) prepared through freeze-thaw cycling and an in situ electron-beam radiation method. The structures and morphologies of g-CP were confirmed using Fourier infrared spectroscopy (FTIR), X-ray diffraction spectroscopy (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), solid ultraviolet diffuse reflectance spectroscopy (UV-vis DRS), and Brunauer-Emmett-Teller (BET). Photocatalytic degradation experiments demonstrated that 1 wt% g-CP degraded rhodamine B (RhB) up to 65.92% in 60 min. At the same time, g-CP had good antimicrobial abilities for Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) within 4 h. The shapes of g-CP were adjustable (such as bar, cylinder, and cube) and had good mechanical properties and biocompatibility. The tensile and compressive modulus of 2 wt% g-CP were 0.093 MPa and 1.61 MPa, respectively. The Cell Counting Kit-8 (CCK-8) test and Hoechst33342/PI double staining were used to prove that g-CP had good biocompatibility. It is expected to be applied to environmental sewage treatment and wound dressing in the future.

Thiolation of Terminal Alkynes with Thiuram Disulfide Reagents Using Water as the Hydrogen Source: Stereoselective Synthesis of (Z)-Vinyl Sulfides.

A stereoselective and environmentally friendly thiolation of terminal alkynes was reported. Thiuram disulfide reagents (tetramethylthiuram disulfide and tetraethylthiuram disulfide) that reacted with alkynes in dimethyl sulfoxide (DMSO)/H2O could give (Z)-vinyl sulfides in good yields (up to 88%). This protocol features broad substrate scope, good stereoselectivity, high atom economy, good yields, and is transition metal-free. Mechanistic studies revealed that water and DMSO served as hydrogen sources, which greatly highlighted the unique reactivity of this special reaction involving two H-atom donors.

Economical Production of Phenazine-1-carboxylic Acid from Glycerol by Pseudomonas chlororaphis Using Cost-Effective Minimal Medium.

Phenazine compounds are widely used in agricultural control and the medicine industry due to their high inhibitory activity against pathogens and antitumor activity. The green and sustainable method of synthesizing phenazine compounds through microbial fermentation often requires a complex culture medium containing tryptone and yeast extract, and its cost is relatively high, which greatly limits the large-scale industrial production of phenazine compounds by fermentation. The aim of this study was to develop a cost-effective minimal medium for the efficient synthesis of phenazine compounds by Pseudomonas chlororaphis. Through testing the minimum medium commonly used by Pseudomonas, an ME medium for P. chlororaphis with a high production of phenazine compounds was obtained. Then, the components of the ME medium and the other medium were compared and replaced to verify the beneficial promoting effect of Fe2+ and NH4+ on phenazine compounds. A cost-effective general defined medium (GDM) using glycerol as the sole carbon source was obtained by optimizing the composition of the ME medium. Using the GDM, the production of phenazine compounds by P. chlororaphis reached 1073.5 mg/L, which was 1.3 times that achieved using a complex medium, while the cost of the GDM was only 10% that of a complex medium (e.g., the KB medium). Finally, by engineering the glycerol metabolic pathway, the titer of phenazine-1-carboxylic acid reached the highest level achieved using a minimum medium so far. This work demonstrates how we systematically analyzed and optimized the composition of the medium and integrated a metabolic engineering method to obtain the most cost-effective fermentation strategy.

Application of image overlapping in percutaneous nephrolithotomy.

OBJECTIVE: To investigate the application of ultrasound and CT image overlap in percutaneous nephrolithotomy (PCNL). METHODS: A total of 140 patients with complicated kidney stones requiring PCNL were prospectively enrolled, from January 2020 to December 2022. These patients were randomly divided into 2 groups, with 70 patients each in the research group and the control group. All participants underwent dual-source, non-contrast CT scan of both kidneys and pelvis before surgery. Preoperative three-dimensional CT reconstruction and simulated puncture were performed in patients from the research group. The best puncture path was determined through ultrasound and CT image overlap. Puncture guided by regular CT and ultrasound was conducted in patients from the control group. Differences in the surgical outcomes between the two groups were compared. RESULTS: Compared to the control group, the research group had higher stone clearance rate in stage I PCNL, success rate of one-time puncture, less percutaneous channels, less reduction of hemoglobin and shorter procedure time. Complications in stage I PCNL were comparable in the two groups, and there was no significant change in the final stone clearance rates between the two groups. CONCLUSION: An optimal puncture channel can be chosen using ultrasound and CT image overlap. PCNL can be achieved with precise puncturing, thus achieving coincidence between imaging and anatomy and reducing the amount of blood loss during stage I of PCNL. It also shortens the procedure time and improves stone clearance rate of PCNL.

Salting-out extraction of recombinant κ-carrageenase and phage T7 released from Escherichia coli cells.

Traditional technology of cell disruption has become one of the bottlenecks restricting the industrialization of genetic engineering products due to its high cost and low efficiency. In this study, a novel bioprocess of phage lysis coupled with salting-out extraction (SOE) was evaluated. The lysis effect of T7 phage on genetically engineered Escherichia coli expressing κ-carrageenase was investigated at different multiplicity of infection (MOI), meanwhile the phage and enzyme released into the lysate were separated by SOE. It was found that T7 phage could lyse 99.9% of host cells at MOI = 1 and release more than 90.0% of enzyme within 90 min. After phage lysis, 87.1% of T7 phage and 71.2% of κ-carrageenase could be distributed at the middle phase and the bottom phase, respectively, in the SOE system composed of 16% ammonium sulfate and 20% ethyl acetate (w/w). Furthermore, κ-carrageenase in the bottom phase could be salted out by ammonium sulfate with a yield of 40.1%. Phage lysis exhibits some advantages, such as mild operation conditions and low cost. While SOE can efficiently separate phage and intracellular products. Therefore, phage lysis coupled with SOE is expected to become a viable alternative to the classical cell disruption and intracellular product recovery.

Revisiting Genetic Epidemiology with a Refined Targeted Gene Panel for Hereditary Hearing Impairment in the Taiwanese Population.

Hearing impairment is one of the most common sensory disorders in children, and targeted next-generation sequencing (NGS)-based genetic examinations can assist in its prognostication and management. In 2020, we developed a simplified 30-gene NGS panel from the original 214-gene NGS version based on Taiwanese genetic epidemiology data to increase the accessibility of NGS-based examinations. In this study, we evaluated the diagnostic performance of the 30-gene NGS panel and compared it with that of the original 214-gene NGS panel in patient subgroups with different clinical features. Data on the clinical features, genetic etiologies, audiological profiles, and outcomes were collected from 350 patients who underwent NGS-based genetic examinations for idiopathic bilateral sensorineural hearing impairment between 2020 and 2022. The overall diagnostic yield was 52%, with slight differences in genetic etiology between patients with different degrees of hearing impairment and ages of onset. No significant difference was found in the diagnostic yields between the two panels, regardless of clinical features, except for a lower detection rate of the 30-gene panel in the late-onset group. For patients with negative genetic results, where the causative variant is undetectable on current NGS-based methods, part of the negative results may be due to genes not covered by the panel or yet to be identified. In such cases, the hearing prognosis varies and may decline over time, necessitating appropriate follow-up and consultation. In conclusion, genetic etiologies can serve as references for refining targeted NGS panels with satisfactory diagnostic performance.

Genetic variation reveals the enhanced microbial hyaluronan biosynthesis via atmospheric and room temperature plasma.

This study reveals the genetic and biochemical changes underlying the enhanced hyaluronan (HA) biosynthesis in Streptococcus zooepidemicus. After multiple rounds of atmospheric and room temperature plasma (ARTP) mutagenesis combined with novel bovine serum albumin/cetyltrimethylammonium bromide coupled high-throughput screening assay, the HA yield of the mutant was increased by 42.9% and reached 0.813 g L-1 with a molecular weight of 0.54 × 106 Da within 18 h by shaking flask culture. HA production was increased to 4.56 g L-1 by batch culture in 5-L fermenter. Transcriptome sequencing exhibits that distinct mutants have similar genetic changes. Regulation in direction of metabolic flow into the HA biosynthesis, by enhancing genes responsible for the biosynthesis of HA including hasB, glmU and glmM, weaking downstream gene (nagA and nagB) of UDP-GlcNAc and significantly down-regulating transcription of wall-synthesizing genes, resulting in the accumulation of precursors (UDP-GlcA and UDP-GlcNAc) increased by 39.74% and 119.22%, respectively. These associated regulatory genes may provide control point for engineering of the efficient HA-producing cell factory.