A recombineering based approach for high-throughput conditional knockout targeting vector construction

Functional analysis of mammalian genes in vivo is primarily achieved through analysing knockout mice. Now that the sequencing of several mammalian genomes has been completed, understanding functions of all the genes represents the next major challenge in the post-genome era. Generation of knockout mutant mice has currently been achieved by many research groups but only by making individual knockouts, one by one. New technological advances and the refinements of existing technologies are critical for genome-wide targeted mutagenesis in the mouse. We describe here new recombineering reagents and protocols that enable recombineering to be carried out in a 96-well format. Consequently, we are able to construct 96 conditional knockout targeting vectors simultaneously. Our new recombineering system makes it a reality to generate large numbers of precisely engineered DNA constructs for functional genomics studies

The molecular mechanism of ferroptosis and its role in COPD

Ferroptosis, a new type of cell death, is mainly characterized by intracellular iron accumulation and lipid peroxidation. The complex regulatory network of iron metabolism, lipid metabolism, amino acid metabolism, p53-related signaling, and Nrf2-related signaling factors is involved in the entire process of ferroptosis. It has been reported that ferroptosis is involved in the pathogenesis of neurological diseases, cancer, and ischemia–reperfusion injury. Recent studies found that ferroptosis is closely related to the pathogenesis of COPD, which, to some extent, indicates that ferroptosis is a potential therapeutic target for COPD. This article mainly discusses the related mechanisms of ferroptosis, including metabolic regulation and signaling pathway regulation, with special attention to its role in the pathogenesis of COPD, aiming to provide safe and effective therapeutic targets for chronic airway inflammatory diseases

Cost-effectiveness analysis of nivolumab combination therapy in the first-line treatment for advanced esophageal squamous-cell carcinoma

ObjectiveWe aimed to investigate the cost-effectiveness of nivolumab plus chemotherapy and nivolumab plus ipilimumab versus chemotherapy in the first-line treatment for advanced esophageal squamous-cell carcinoma (ESCC) patients from a healthcare system perspective in China.MethodsOn the basis of the CheckMate 648 trial, a partitioned survival model was constructed to estimate economic costs and health outcomes among overall and PD-L1-positive advanced ESCC patients over a 10-year lifetime horizon. The health-related costs and utilities were obtained from the local charges and published literature. The lifetime costs, life-years, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratio (ICER) were measured. One-way and probabilistic sensitivity analyses (PSA) were performed to assess the robustness of the model.ResultsIn the base-case analysis, in overall and PD-L1-positive advanced ESCC patients, the ICERs were $415,163.81/QALY and$216,628.00/QALY for nivolumab plus chemotherapy, and$430,704.11/QALY and$185,483.94/QALY for nivolumab plus ipilimumab, respectively, compared with chemotherapy. One-way sensitivity analyses revealed that patients’ weight was the most influential parameter on ICER. The PSA demonstrated that the probability of nivolumab combination therapy being cost-effective was 0% over chemotherapy at the current price and willingness-to-pay threshold ($38,351.20/QALY). When the price of nivolumab and ipilimumab decreased 80%, the cost-effective probability of nivolumab plus ipilimumab increased to 40.44% and 86.38% in overall and PD-L1-positive advanced ESCC patients, respectively.ConclusionNivolumab combination therapy could improve survival time and health benefits over chemotherapy for advanced ESCC patients, but it is unlikely to be a cost-effective treatment option in China

Effect of Different Tumbling Marination Treatments on the Quality Characteristics of Prepared Pork Chops

The effect of different tumbling marination treatments (control group, CG; conventional static marination, SM; vacuum continuous tumbling marination, CT; vacuum intermittent tumbling marination, IT) on the quality characteristics of prepared pork chops was investigated under simulated commercial conditions. The CT treatment increased (p<0.05) the pH value, b* value, product yield, tenderness, overall flavor, sensory juiciness and overall acceptability in comparison to other treatments for prepared boneless pork chops. The CT treatment decreased (p<0.05) cooking loss, shear force value, hardness, gumminess and chewiness compared with other treatments. In addition, CT treatment effectively improved springiness and sensory color more than other treatments. However, IT treatment achieved the numerically highest (p<0.05) L* and a* values. These results suggested that CT treatment obtained the best quality characteristics of prepared pork chops and should be adopted as the optimal commercial processing method for this prepared boneless pork chops

Evaluation of the IP-10 mRNA release assay for diagnosis of TB in HIV-infected individuals

HIV-infected individuals are susceptible to Mycobacterium tuberculosis (M.tb) infection and are at high risk of developing active tuberculosis (TB). Interferon-gamma release assays (IGRAs) are auxiliary tools in the diagnosis of TB. However, the performance of IGRAs in HIV-infected individuals is suboptimal, which limits clinical application. Interferon-inducible protein 10 (IP-10) is an alternative biomarker for identifying M.tb infection due to its high expression after stimulation with M.tb antigens. However, whether IP-10 mRNA constitutes a target for the diagnosis of TB in HIV-infected individuals is unknown. Thus, we prospectively enrolled HIV-infected patients with suspected active TB from five hospitals between May 2021 and May 2022, and performed the IGRA test (QFT-GIT) alongside the IP-10 mRNA release assay on peripheral blood. Of the 216 participants, 152 TB patients and 48 non-TB patients with a conclusive diagnosis were included in the final analysis. The number of indeterminate results of IP-10 mRNA release assay (13/200, 6.5%) was significantly lower than that of the QFT-GIT test (42/200, 21.0%) (P = 0.000026). IP-10 mRNA release assay had a sensitivity of 65.3% (95%CI 55.9% – 73.8%) and a specificity of 74.2% (95%CI 55.4% – 88.1%), respectively; while the QFT-GIT test had a sensitivity of 43.2% (95%CI 34.1% – 52.7%) and a specificity of 87.1% (95%CI 70.2% – 96.4%), respectively. The sensitivity of the IP-10 mRNA release assay was significantly higher than that of QFT-GIT test (P = 0.00062), while no significant difference was detected between the specificities of these two tests (P = 0.198). The IP-10 mRNA release assay showed a lower dependence on CD4+ T cells than that of QFT-GIT test. This was evidenced by the fact that the QFT-GIT test had a higher number of indeterminate results and a lower sensitivity when the CD4+ T cells counts were decreased (P &lt; 0.05), while no significant difference in the number of indeterminate results and sensitivity were observed for the IP-10 mRNA release assay among HIV-infected individuals with varied CD4+T cells counts (P &gt; 0.05). Therefore, our study suggested that M.tb specific IP-10 mRNA is a better biomarker for diagnosis of TB in HIV-infected individuals

Political Resource Curse under Authoritarianism: Evidence from China *

Abstract By analyzing a panel constructed on the political turnovers of 4,390 county leaders in China during 1999-2008, we find that the revenue windfalls accrued to these officials from land sales since 1998 have both undermined the effectiveness of the promotion system for government officials and fueled corruption. Instead of rewarding efforts made to boost GDP growth, promotion is now also positively correlated with signaling efforts or specifically increased spending on flamboyant (so-called &quot;image&quot;) public projects, with those politically connected to their superiors and those who are beyond the prime age for promotion being the primary beneficiaries. Likewise, the same revenue windfalls have also led to corruption, as gauged from the increases in the government workforce and administrative expenditure but not social welfare spending. Our findings highlight how land revenue windfalls can lead to a political resource curse in a highly politically centralized authoritarian regime

Corneal Surface Ablation Laser Refractive Surgery for the Correction of Myopia: A Network Meta-analysis

PURPOSE: To systematically compare the efficacy, predictability, safety, postoperative haze, pain scores, and epithelial healing time of four corneal surface ablation procedures. METHODS: PubMed, Embase, Cochrane Library, and the U.S. trial registry were searched up to June 2018. Randomized controlled trials were selected. Efficacy (uncorrected distance visual acuity of 20/20 or better), predictability (refractive spherical equivalent within ±0.50 diopters [D] of the target), and safety (loss of two or more lines of spectacle corrected distance visual acuity) were set as primary outcome measures. Haze, pain scores, and epithelial healing time were set as secondary outcome measures. RESULTS: Eighteen studies involving 1,423 eyes were included. According to the Grading of Recommendations Assessment, Development, and Evaluation, the quality of outcomes were moderate to high (70.6%). There were no differences in efficacy, predictability, safety, haze, day 1 pain, and epithelial healing time between treatments. Epithelial laser in situ keratomileusis (epi-LASIK) had statistically significantly higher pain scores on day 3 compared to photorefractive keratectomy (PRK) (weighted mean differences [WMD] = 2.2, 95% credible intervals [CrI] = 0.19 to 4.01) and transepithelial PRK (T-PRK) (WMD = 2.7, 95% CrI = 0.51 to 4.84). The surface under the cumulative ranking curve ranking results (best to worst) showed laser epithelial keratomileusis (LASEK) ranked highest for efficacy, predictability, safety, and day 1 pain scores. Epi-LASIK ranked best for grade 1 haze scores. T-PRK ranked best for haze of 0.5 or higher, haze scores day 3 pain scores, and epithelial healing time. CONCLUSIONS: Surface laser refractive surgeries are comparable in terms of efficacy, predictability, safety, and postoperative haze except for day 3 pain scores, with epi-LASIK being more painful compared to PRK and T-PRK. [J Refract Surg. 2018;34(11):726-735.]

Study on Soil Microbial Diversity of Cymbidium goeringii and Cymbidium faberi in Qinling Mountains after Introduction and Domestication

Rhizosphere microbial communities have abundant species and a large number, and affect the physiology and growth of plants. When studying rhizosphere microbes, the rhizosphere ecosystem function and protection of wild orchids will be facilitated. By using high-throughput sequencing technology, the rhizosphere and non-rhizosphere bacteria and fungi of wild Cymbidium goeringii and Cymbidium faberi in the Qinling Mountains were analyzed at phylum, class, order, family, and genus levels to explore the rhizosphere bacterial and fungal community structure and diversity of orchid plants (C. goeringii and C. faberi) under natural conditions. The results showed that at the phylum level Proteobacteria was dominant in rhizosphere and non-rhizosphere soil of C. goeringii and C. faberi, but the proportion was different. The abundance of Proteobacteria in rhizosphere soil of C. faberi was the highest (35.5%), which was about 1.3 times of that in non-rhizosphere soil. Bacteroidetes accounted for 17.2% in rhizosphere soil of C. goeringii, much higher than that of non-rhizosphere soil (7.92%). The dominant groups of fungi in rhizosphere soil of C. goeringii and C. faberi were both Ascomycota. At the genus level, PCoA analysis showed that the community structure of bacteria and fungi in different samples was not only common but also specific, which was manifested in the similar dominant species but different subdominant species. This difference is reflected in the composition and relative abundance of microbial communities between different samples, and will gradually become obvious with the refinement of genera

Calibration and Validation of a Mean Value Model for Turbocharged Diesel Engine

In order to meet the high requirements of the control strategies for an effective and accuracy control-oriented model, a mean value model for a turbocharged diesel engine has been developed on the Matlab/Simulink. And then the error sources leading to the simulation inaccuracy have been analyzed comprehensively and two sets of experiments for model calibration and validation have been designed. Then a model calibration process and a model validation process have been proposed, with which the developed model is well calibrated and validated against the two sets of experimental data. Especially, for the compressor model calibration, an improved Jensen and Kristense method has been introduced to interpolate and extend the compressor maps. And turbine efficiency observer is designed for the rectification of turbine maps. At last, the calibration and validation process and improved methods and observer for turbocharger are verified and evaluated