ISAba1 mediated intrinsic chromosomal oxacillinase amplification confers carbapenem resistance in Acinetobacter baumannii.

Tandem amplification of carbapenemase genes increases gene copy number and enhances carbapenem resistance. These amplifications are often heterogeneous, transient, and located on plasmids, which also contribute to heteroresistance. Amplification of encoding genes is especially important for enzymes with low hydrolysis activity, which are often overlooked. Here, we reported an intrinsic oxacillinase oxaAb amplification flanked by ISAba1. The amplification is in the chromosome and contains up to twenty-five repeats. We provided genomic, transcriptomic, and proteomic evidence that the amplification resulted in oxacillinase overproduction. Notably, no point mutations of oxaAb were found during the amplification process. Strains of A. baumannii with intrinsic amplified or external transformed ISAba1-oxaAb exhibited higher meropenem hydrolysis activity. Furthermore, the number of repeats in the amplification decreased gradually over a period of 21 days cultured with carbapenem withdrawal. However, upon re-exposure to meropenem, the ISAba1 flanked oxaAb responded rapidly, with repeat numbers reaching or exceeding pre-carbapenem withdrawal levels within 24 hours. Taken together, these findings suggest that ISAba1-mediated gene amplification and overproduction of intrinsic low-activity oxacillinase oxaAb resulted in carbapenem resistance.

Prediction models for deep vein thrombosis after knee/hip arthroplasty: A systematic review and network meta-analysis.

Deep vein thrombosis (DVT) is one of the common complications after joint replacement, which seriously affects the quality of life of patients. We systematically searched nine databases, a total of eleven studies on prediction models to predict DVT after knee/hip arthroplasty were included, eight prediction models for DVT after knee/hip arthroplasty were chosen and compared. The results of network meta-analysis showed the XGBoost model (SUCRA 100.0%), LASSO (SUCRA 84.8%), ANN (SUCRA 72.1%), SVM (SUCRA 53.0%), ensemble model (SUCRA 40.8%), RF (SUCRA 25.6%), LR (SUCRA 21.8%), GBT (SUCRA 1.1%), and best prediction performance is XGB (SUCRA 100%). Results show that the XGBoost model has the best predictive performance. Our study provides suggestions and directions for future research on the DVT prediction model. In the future, well-designed studies are still needed to validate this model.

Challenges and Solutions in the Recombinant Expression of Membrane Proteins.

Membrane proteins are important components of the proteome and play key roles in many biological processes, such as signal transduction, material transport, cell recognition, etc. Membrane proteins are involved in several fields, and more and more researchers want to understand them. However, the structural properties of membrane proteins make their recombinant expression yield low. This adversely affects the study of the structure and function of membrane proteins. Therefore, it is crucial to have a comprehensive and up-to-date understanding of membrane protein recombinant expression. Based on the current stage of research on membrane proteins, the article describes the current challenges faced by membrane protein recombinant expression and the solutions that can be applied to lay the foundation for a better study of membrane proteins in the future.

Comparative effectiveness of different exercise interventions for elderly patients with hip fracture: A systematic review and Bayesian network meta-analysis protocol of randomized controlled trials.

BACKGROUND: Exercise intervention (EI) is a promising and economical way for elderly patients with hip fracture, but the evidence regarding effective EIs remains fragmented and controversial, and it is unclear which type of exercise is optimal. The purpose of this Bayesian network meta-analysis (NMA) is to compare and rank the efficacy of various EIs in elderly patients with hip fracture. MATERIALS AND METHODS: A comprehensive literature search was performed using a systematic approach across various databases including Medline (via PubMed), CINAHL, CNKI, Web of Science, Wan Fang, Embase, VIP, Cochrane Central Register of Controlled Trials and CBM databases. The search encompasses all available records from the inception of each database until December 2022. The Inclusion literature comprises randomized controlled trials that incorporate at least one EI for elderly patients with hip fracture. We will assess the risk of bias of the studies in accordance with the Cochrane Handbook for Systematic Reviews of Interventions, and assess each evidence of outcome quality in accordance with the Grading of Recommendations Assessment, Development and Evaluation framework. The NMA will be performed by STATA 15.0 software and OpenBUGS version 3.2.3. The identification of publication bias will be accomplished through the utilization of a funnel plot. We will rank the EIs effects according to the cumulative ranking probability curve (surface under the cumulative ranking area, SUCRA). The primary outcomes will be hip function in elderly patients, and the secondary outcomes will be activities of daily living, walking capacity and balance ability of elderly patients. TRIAL REGISTRATION: PROSPERO registration number: CRD4202022340737.

Helicobacter macacae MazF interplays with Escherichia coli homologs and enhances antibiotic tolerance.

BACKGROUND: Toxin-antitoxin systems are highly variable, even among strains of the same bacterial species. The MazEF toxin-antitoxin system is found in many bacteria and plays important roles in various biological processes such as antibiotic tolerance and phage defense. However, no interplay of MazEF systems between different species was reported. MATERIALS AND METHODS: MazEF toxin-antitoxin system of Helicobacter macacae was examined in three Escherichia coli strains with and without endogenous MazEF knockout. In vivo toxicity, antibiotic tolerance, and live/dead staining followed by flowcytometry analysis were performed to evaluate the functionality and interplay of the toxin-antitoxin system between the two species. RESULTS: Controlled ectopic expression of MazF of H. macacae (MazFhm) in E. coli did not affect its growth. However, in endogenous MazEF knockout E. coli strains, MazFhm expression caused a sharp growth arrest. The toxicity of MazFhm could be neutralized by both the antitoxin of MazE homolog of H.macacae and the antitoxin of MazE of E. coli, indicating interplay of MazEF toxin-antitoxin systems between the two species. Induced expression of MazFhm enhanced tolerance to a lethal dose of levofloxacin, suggesting enhanced persister formation, which was further confirmed by live/dead cell staining. CONCLUSIONS: The MazEF toxin-antitoxin system of H. macace enhances persister formation and thus antibiotic tolerance in E. coli. Our findings reveal an interplay between the MazEF systems of H. macacae and E. coli, emphasizing the need to consider this interaction while evaluating the toxicity and functionality of MazF homologs from different species in future studies.

Application of 3D-Printed Personalized Guide for Lateral Femoral Positioning in Anterior Cruciate Ligament Reconstruction of the Knee.

Objective: This research aims to investigate the effectiveness of 3D computer-assisted customized guided positioning of the lateral femoral tunnel compared to conventional methods for Anterior Cruciate Ligament (ACL) reconstruction surgery. Methods: A total of 80 patients with a complete ACL tear who underwent arthroscopic reconstruction with autologous tendon transplantation (semitendinosus-gracilis tendon) were included in this study. The patients were admitted to our hospital between March 2020 and January 2022 and were randomly divided into two groups: the conventional group (n = 40) and the personalized guide group (n = 40), based on the positioning method. The conventional group underwent ACL restoration using standard surgical techniques, while the personalized guide group opted for the more precise computer-assisted personalized guide method. The lateral femoral tunnel times were compared between both groups. Additionally, the International Knee Documentation Committee (IKDC) and Lysholm scores were assessed, and the lateral femoral location was evaluated using X-ray imaging at 2 weeks postoperatively. Results: After surgery, both groups showed a statistically significant increase (P < .05) in Lysholm and IKDC scores compared to their pre-surgery scores. However, the two groups had no evident difference (P > .05). X-ray evaluation at 2 weeks post-surgery revealed no significant difference between the two groups in NL/ML, AL/BL, α, and ß angles (P > .05). The preparation time for the femoral tunnel was significantly shorter in the personalized guide group (6.18 ± 0.92 min) compared to the traditional group (15.94 ± 3.12 min) (P < .05). Conclusions: The computer-assisted 3D personalized guide positioning method is more effective in locating the lateral femoral tunnel for ACL reconstruction of the knee and can substantially reduce the positioning time. This study provides valuable insights for clinicians when selecting surgical methods.

Long-Read- and Short-Read-Based Whole-Genome Sequencing Reveals the Antibiotic Resistance Pattern of Helicobacter pylori.

The rates of antibiotic resistance of Helicobacter pylori are increasing, and the patterns of resistance are region and population specific. Here, we elucidated the antibiotic resistance pattern of H. pylori in a single center in China and compared short-read- and long-read-based whole-genome sequencing for identifying the genotypes. Resistance rates of 38.5%, 61.5%, 27.9%, and 13.5% against clarithromycin, metronidazole, levofloxacin, and amoxicillin were determined, respectively, while no strain was resistant to tetracycline or furazolidone. Single nucleotide variations (SNVs) in the 23S rRNA and GyrA/B genes revealed by Illumina short-read sequencing showed good diagnostic abilities for clarithromycin and levofloxacin resistance, respectively. Nanopore long-read sequencing also showed a good efficiency in elucidating SNVs in the 23S rRNA gene and, thus, a good ability to detect clarithromycin resistance. The two technologies displayed good consistency in discovering SNVs and shared 76% of SNVs detected in the rRNA gene. Taking Sanger sequencing as the gold standard, Illumina short-read sequencing showed a slightly higher accuracy for discovering SNVs than Nanopore sequencing. There are two copies of the rRNA gene in the genome of H. pylori, and we found that the two copies were not the same in at least 26% of the strains tested, indicating their heterozygous status. Especially, three strains harboring a 2143G/A heterozygous status in the 23S rRNA gene, which is the most important site for clarithromycin resistance, were found. In conclusion, our results provide evidence for an empirical first-line treatment for H. pylori eradication in clinical settings. Moreover, we show that Nanopore sequencing is a potential tool for predicting clarithromycin resistance. IMPORTANCE Helicobacter pylori resistance has been increasing in recent years. The resistance profile, which is important for empirical treatment, is region and population specific. We found high rates of resistance to metronidazole, clarithromycin, and levofloxacin in H. pylori in our center, while no resistance to tetracycline or furazolidone was found. These results provide a reference for local physicians prescribing antibiotics for H. pylori eradication. Nanopore sequencing recently appeared to be a promising technology for elucidating whole-genome sequences, which generates long sequencing reads and is time-efficient and portable. However, a relatively higher error rate of sequencing reads was also found. In this study, we compared Nanopore sequencing and Illumina sequencing for revealing single nucleotide variations in the 23S rRNA gene, which determines clarithromycin resistance, and we found that although there were a few false discoveries, Nanopore sequencing showed good consistency with Illumina sequencing, indicating that it is a potential tool for predicting clarithromycin resistance.

Observation of the curative effect of scleral suture fixation technique with four-loop foldable intraocular lens.

The objective of the study was to evaluate the curative effect of a modified technique of scleral suture fixation with a four-loop foldable intraocular lens (IOL) for eye with inadequate capsule support. This was a retrospective study of 22 eyes with inadequate capsule support of 20 patients who underwent the scleral suture fixation technique with 9-0 polypropylene suture and foldable four-loop IOL implant. Preoperative and follow-up data were collected for all patients. The mean follow-up was 5.08 ± 0.48 months (range: 3-12 months). The mean pre- and postoperative log of minimum angle of resolution (logMAR) uncorrected distance visual acuity was 1.11 ± 0.32 versus 0.09 ± 0.09 (P < 0.001). The mean pre- and postoperative logMAR best corrected visual acuity was 0.37 ± 0.19 versus 0.08 ± 0.07 (P < 0.001). The intraocular pressure (IOP) increased briefly (range: 21-30 mmHg) in eight eyes on the first day postoperatively and returned to normal within 1 week. No IOP drops were used postoperatively. The IOP was 12-19.3 (13.72 ± 1.28) in this follow-up, which had no significant difference compared to the preoperative IOP (t = 0.34, P = 0.74). At this follow-up, there was no hyperemia, local hyperplasia, obvious scar, suture knots, or segment ends observed under the conjunctiva, as well as no pupil deformation or vitreous hemorrhage. The mean postoperative IOL decentration degree was 0.22 ± 0.08 mm. At the 7-day follow-up postoperatively, one side of the IOL was dislocated to the vitreous cavity in one case, which was resolved by reimplantation of a new IOL in time with the same technique. Scleral suture fixation technique of a four-loop foldable IOL was a feasible operation method for an eye with inadequate capsular support.

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Fulvic acid (FA) participates in the regulation of drought stress tolerance in plants, but the underlying mechanisms remain unclear. We carried out an experiment with cucumber cultivar 'Jinyou 35' as the test material and the polyethylene glycol (PEG-6000) being used to simulate drought stress. The concentration effect of FA on drought alleviation of cucumber as well as the effect of FA on photosynthetic enzymes activities, chloroplast ultrastructure, fluorescence parameters, water use efficiency, yield and quality of cucumber plants were studied through spraying FA with different concentrations (0, 100, 300, 500, 700 and 900 mg·L-1). The results showed that FA with different concentrations significantly promoted the relative water content and leaf area and decreased drought injure index as well as the electrolyte leakage and malondialdehyde (MDA) content, compared with the control (0 mg·L-1) under drought stress. The mitigative effect of FA increased first and then decreased with the increases of FA concentration, with 700 mg·L-1 FA showing the best effect. FA significantly enhanced the chlorophyll content, Rubiasco and Rubisco activase (RCA) activities and gene expression, net photosynthesis (Pn), maximal photochemical efficiency of PSⅡin darkness, actual photochemical efficiency, absorbed light energy per unit area, captured light energy per unit area, quantum yield of electron transport and PSⅠ activity, decreased the increase of K point and maintained chloroplast ultrastructure. The experiment in solar-greenhouse showed that FA obviously increased water use efficiency, promoted dry matter accumulation as well as the contents of Vc, soluble sugar, soluble protein and free amino acid, and decreased tannin content. Our results suggested that FA could improve the yield and quality of cucumber in solar greenhouse under drought stress.

Effects of Cognitive Nursing Combined with Continuous Nursing on Postpartum Mental State and Rehabilitation.

PURPOSE: This study is aimed at exploring the effects of cognitive nursing combined with continuous nursing on postpartum mental state and rehabilitation. METHODS: Totally, 124 puerperas admitted to our hospital from January 2019 to January 2020 were selected and divided into a research group and a control group according to different nursing methods, with 62 cases in each group. The control group received routine care, while the research group received cognitive nursing combined with continuous nursing on this basis. The mental state, rehabilitation indicators, quality of life, incidence of complications, and nursing satisfaction were compared between the two groups after intervention. RESULTS: Before nursing, there was no statistically significant difference in the SAS and SDS scores between the two groups (P > 0.05); after intervention, the SAS and SDS scores of the two groups were significantly reduced, and those of the research group were lower than those of the control group (P < 0.05). After intervention, the time of the first breastfeeding, duration of lochia rubra, length of hospital stay, and score of uterine contraction pain of the research group were lower than those of the control group (P < 0.05); the psychological function, physical function, material life, and social function scores of the research group were higher than those of the control group (P < 0.05); the incidence of complications in the research group was 4.84%, lower than 20.97% in the control group (P < 0.05); the nursing satisfaction of the research group was 96.77%, which was significantly higher than 83.87% in the control group (P < 0.05). CONCLUSIONS: Cognitive nursing combined with continuous nursing can effectively improve the mental state, shorten the length of hospital stay, increase the perceived well-being, and promote the physical rehabilitation in puerperas, which is worth promoting in clinical practice.

Modified Technique for Scleral-Sutured Fixation with the Double Knots Technique for Posterior Chamber Intraocular Lens: Short-Term Observation.

PURPOSE: To evaluate the short-term safety and efficacy of a novel approach of utilizing the 9-0 looped polypropylene suture with double knots buried into the scleral groove and the scleral tunnel to minimize the risk of the suture erosion and suture knot exposure. DESIGN: Clinical-based retrospective study. METHODS: Records of consecutive patients who had anterior vitrectomy and scleral-fixated posterior chamber intraocular lens (IOL) implantation between July 2018 and April 2020 with a minimum follow-up of 3 months were reviewed. RESULTS: This study enrolled a total of 21 eyes from 20 patients (15 male). These patients had a mean age of 58.52 ± 8.55 years and were followed for an average of 1.08 ± 0.58 years postoperatively. Best-corrected visual acuity (BCVA) improved from a preoperative mean of 0.43 ± 0.41 logMAR to a significantly higher mean 3-month postoperative value of 0.09 ± 0.21 logMAR (Z = -3.35, p < 0.01). There were no statistical differences between the preoperative and postoperative corneal endothelial cell density (p=0.71). The postoperative complications included transient increased intraocular pressure in 5 eyes (24%). No other complications were detected during the follow-up. CONCLUSIONS: The modified technique proposed is a safe, effective, and reliable approach resulting in good visual outcomes. Our procedure might have the potential benefit to avoid suture-related complications in scleral-fixated IOL implantation. Trial registration. Retrospective case series study, not applicable.

Prevalence and Age-Related Changes of Corneal Astigmatism in Patients Undergoing Cataract Surgery in Northern China.

PURPOSE: To examine the magnitude, orientation, and age-related changes of corneal astigmatism of the eyes before cataract surgery. Setting. Hebei Eye Hospital, Hebei, China. DESIGN: A clinical-based retrospective study. RESULTS: The study consisted of 5662 eyes of 5662 consecutive cataract surgery patients with a mean age of 68.26 ± 10.39 (mean ± standard deviation (SD)) years (range 40 to 97 years), and 59.86% of the patients were women. Mean corneal astigmatism was 0.98 ± 0.76 diopter (D) (range 0.00-9.61 D). Corneal astigmatism of 0.50-0.99 D was the most common range of values (30.08%), followed by 1.00-1.49 D (22.15%), ≤0.50 D (21.21%), and 1.50-1.99 D (10.28%). There was a strong U-shaped relation between corneal astigmatism and age (p for nonlinearity <.01). With the increase of age, the astigmatism axis gradually changes from with-the-rule (WTR) to against-the-rule (ATR). Moreover, in young patients with age below 65 years, WTR astigmatism was negatively correlated with age, while ATR was positively correlated with age (r = -0.11, p=.001; r = 0.10, p=.010, respectively). However, in the old patients with age above and equal to 65 years, all types of astigmatism were positively correlated with age. CONCLUSION: This study may provide valuable and practical information to surgeons when selecting the appropriate surgical method and toric intraocular lens (IOLs).

Toward Green Production of Chewing Gum and Diet: Complete Hydrogenation of Xylose to Xylitol over Ruthenium Composite Catalysts under Mild Conditions.

Xylitol is one of the most famous chemicals known to people as the essential ingredient of chewing gum and as the sugar alternative for diabetics. Catalytic hydrogenation of biomass-derived xylose with H2 to produce high-value xylitol has been carried out under harsh reaction conditions. Herein, we exhibit the combination of Ru NPs with an environmentally benign MOF (ZIF-67) to afford a heterogeneous composite catalyst. Complete conversion of xylose with 100% selectivity to xylitol was achieved at 50°C and 1 atm H2. This is the first successful attempt to produce xylitol with ambient pressure H2 as well as the first time to achieve a 100% selectivity of xylitol for applicable catalysts. We also proved the universality of the Ru@ZIF-67 towards other hydrogenation processes. Under 1 atm H2, we achieved 100% conversion and >99% selectivity of 1-phenylethanol at 50°C for the hydrogenation of acetophenone. This is also the first report of hydrogenating acetophenone to 1-phenylethanol under 1 atm H2, which confirms that our result not only contributes to enhance the industrial yields of xylitol and reduces both the economical and energy costs but also provides new perspectives on the other hydrogenation process with H2.