A rapid and ultra-sensitive dual readout platform for Klebsiella pneumoniae detection based on RPA-CRISPR/Cas12a.

The bacterium Klebsiella pneumoniae (Kp) was the primary pathogen of hospital-acquired infection, but the current detection method could not rapidly and conveniently identify Kp. Recombinase polymerase amplification (RPA) was a fast and convenient isothermal amplification technology, and the clustered regularly interspaced short palindromic repeats (CRISPR) system could rapidly amplify the signal of RPA and improve its limit of detection (LOD). In this study, we designed three pairs of RPA primers for the rcsA gene of Kp, amplified the RPA signal through single-strand DNA reporter cleavage by CRISPR/Cas12a, and finally analyzed the cleavage signal using fluorescence detection (FD) and lateral flow test strips (LFTS). Our results indicated that the RPA-CRISPR/Cas12a platform could specifically identify Kp from eleven common clinical pathogens. The LOD of FD and LFTS were 1 fg/µL and 10 fg/µL, respectively. In clinical sample testing, the RPA-CRISPR/Cas12a platform was consistent with the culture method and qPCR method, and its sensitivity and specificity were 100% (16/16) and 100% (9/9), respectively. With the advantages of detection speed, simplicity, and accuracy, the RPA-CRISPR/Cas12a platform was expected to be a convenient tool for the early clinical detection of Kp.

Linearly Polarized Broadband Emission and Multiwavelength Lasing in Solution-Processed Quantum Dots.

A miniature laser with linear polarization is a long sought-after component of photonic integrated circuits. In particular, for multiwavelength polarization lasers, it supports simultaneous access to multiple, widely varying laser wavelengths in a small spatial region, which is of great significance for advancing applications such as optical computing, optical storage, and optical sensing. However, there is a trade-off between the size of small-scale lasers and laser performance, and multiwavelength co-gain of laser media and multicavity micromachining in the process of laser miniaturization remain as significant challenges. Herein, room-temperature linearly polarized multiwavelength lasers in the visible and near-infrared wavelength ranges are demonstrated, by fabricating random cavities scattered with silica in an Er-doped Cs2Ag0.4Na0.6In0.98Bi0.02Cl6 double-perovskite quantum dots gain membrane. By regulating the local symmetry and enabling effective energy transfer in nanocrystals, multiwavelength lasers with ultralow thresholds are achieved at room temperature. The maximum degree of polarization reaches 0.89. With their advantages in terms of miniaturization, ultralow power consumption, and adaptability for integration, these lasers offer a prospective light source for future photonic integrated circuits aimed at high-capacity optical applications.

A dual RPA-LFD assay for the simultaneous detection of Salmonella typhimurium and Salmonella enteritidis.

Introduction: Salmonella was one of the most common bacteria that caused foodborne illness, with S. typhimurium (Salmonella typhimurium) and S. enteritidis (Salmonella enteritidis) infections accounting for more than 75% of human salmonella infections. Methods: In this study, we developed a method of dual recombinase polymerase amplification (RPA) combined with a lateral flow dipstick for the rapid detection of S. typhimurium and S. enteritidis in clinical specimens (stool). Results: The entire reaction process, including amplification and result reading, could be completed within 65 min. The detection limits of S. typhimurium and S. enteritidis in pure culture samples were 5.23 × 101 CFU/mL and 3.59 × 101 CFU/mL, respectively. The detection limits of S. typhimurium and S. enteritidis in artificially contaminated samples were 8.30 × 101 CFU/mL and 2.70 × 102 CFU/mL, respectively. In addition, the method had no cross-reaction with other pathogenic microorganisms. The results in clinical samples were fully consistent with those obtained using Bacterial Analysis Manual, with sensitivity and specificity were 100% (8/8) and 100% (17/17) for S. typhimurium and 100% (4/4) and 100% (21/21) for S. enteritidis, respectively. Discussion: The detection limits of S. typhimurium and S. enteritidis in artificially contaminated samples were higher than those in pure culture samples, which might be attributed to the inherent complex composition of artificially contaminated samples. In addition, the detection limits of S. typhimurium and S. enteritidis in the same sample were also different, which might be attributed to different amplification efficiency of two target genes in the same reaction system. Conclusion: This assay had potential application outdoors, as it could be performed within 1 h at 38°C without a complex instrument, and the results could be observed with the naked eye. In conclusion, the dual RPA-LFD assay established in this study had practical significance for the rapid detection of S. typhimurium and S. enteritidis in the future.

A multiplex RPA coupled with CRISPR-Cas12a system for rapid and cost-effective identification of carbapenem-resistant Acinetobacter baumannii.

Background: Carbapenem-resistant Acinetobacter baumannii (CRAB) poses a severe nosocomial threat, prompting a need for efficient detection methods. Traditional approaches, such as bacterial culture and PCR, are time-consuming and cumbersome. The CRISPR-based gene editing system offered a potential approach for point-of-care testing of CRAB. Methods: We integrated recombinase polymerase amplification (RPA) and CRISPR-Cas12a system to swiftly diagnose CRAB-associated genes, OXA-51 and OXA-23. This multiplex RPA-CRISPR-Cas12a system eliminates bulky instruments, ensuring a simplified UV lamp-based outcome interpretation. Results: Operating at 37°C to 40°C, the entire process achieves CRAB diagnosis within 90 minutes. Detection limits for OXA-51 and OXA-23 genes are 1.3 × 10-6 ng/µL, exhibiting exclusive CRAB detection without cross-reactivity to common pathogens. Notably, the platform shows 100% concordance with PCR when testing 30 clinical Acinetobacter baumannii strains. Conclusion: In conclusion, our multiplex RPA coupled with the CRISPR-Cas12a system provides a fast and sensitive CRAB detection method, overcoming limitations of traditional approaches and holding promise for efficient point-of-care testing.

Evaluation of Xpert MTB/RIF assay for the diagnosis of extrapulmonary tuberculosis in Southwest China.

The purpose of this study was to determine the diagnostic efficacy of Xpert MTB/RIF assay for rapid diagnosis of Tuberculosis (TB) and detection of rifampicin (RIF) resistance in patients suspected of having EPTB, assessing it against traditional culture and drug susceptibility test (DST) by proportional method, and the ability to predict multidrug resistance TB by Xpert MTB/RIF assay. In this study, the Xpert MTB/RIF assay was applied to 1,614 extrapulmonary specimens. Compared with TB culture and Composite Reference Standard (CRS), the Xpert MTB/RIF assay had a high sensitivity and specificity for detection of EPTB. Depending on the culture method or CRS as the standard, sensitivity of the Xpert MTB/RIF assay for detection of MTB in pleural effusion, cerebrospinal fluid, thoracic drainage fluid and throat swabs specimens were lower than that of other specimens. According to the experimental results, we have reason to believe that Xpert MTB/RIF assay is a rapid and simple technique with high sensitivity and specificity for diagnosing EPTB and detecting drug resistance in variety of specimens. Xpert MTB/RIF assay combined with DST maybe identify more cases of multi-drug resistant tuberculosis (MDR-TB).

Recent advances in recombinase polymerase amplification: Principle, advantages, disadvantages and applications.

After the outbreak of SARS-CoV-2, nucleic acid testing quickly entered people's lives. In addition to the polymerase chain reaction (PCR) which was commonly used in nucleic acid testing, isothermal amplification methods were also important nucleic acid testing methods. Among several common isothermal amplification methods like displaced amplification, rolling circle amplification, and so on, recombinase polymerase amplification (RPA) was recently paid more attention to. It had the advantages like a simple operation, fast amplification speed, and reaction at 37-42°C, et al. So it was very suitable for field detection. However, there were still some disadvantages to RPA. Herein, our review mainly summarized the principle, advantages, and disadvantages of RPA. The specific applications of RPA in bacterial detection, fungi detection, virus detection, parasite detection, drug resistance gene detection, genetically modified food detection, and SARS-CoV-2 detection were also described. It was hoped that the latest research progress on RPA could be better delivered to the readers who were interested in RPA.

Luminescence, energy transfer, colour modulation and up-conversion mechanisms of Yb3+, Tm3+ and Ho3+ co-doped Y6MoO12.

A series of novel up-conversion luminescent Yb3+/Ln3+ (Tm3+, Ho3+, Tm3+/Ho3+)-doped Y6MoO12 (YMO) nanocrystals were synthesized using the sol-gel method. The consistent spherical morphology of the nanocrystals with different doping ratios was found to be profiting from the homogenisation and rapid agglomeration of the composition in the gel state and calcining process. The X-ray diffraction (XRD) and field-emission scanning electron microscope images were employed to confirm perfect crystallinity and uniform morphology. Photoluminescence spectra and decay curves were used to characterize the optical properties of the synthesized samples. The YMO:Yb3+/Ln3+ (Tm3+, Ho3+, Tm3+/Ho3+) nanocrystals were excited by near-infrared photons and emitted photons distributed in blue, green, and red bands with a wide colour gamut, and even white colour, by optimising the relative doping concentrations of the activator ions. The energy conversion mechanism in the up-conversion process was studied using power-dependent luminescence and is depicted in the energy level diagram. In addition, 70% of the luminescence intensity of YMO can be preserved after annealing at 700 °C, and the temperature sensing was tested in the range 298-498 K. These merits of multicolour emissions in the visible region and good stability endow the as-prepared nanocrystals with potential applications in the fields of optical data storage, encryption, sensing, and other multifunctional photonic technologies.

Erratum: Vitexin Inhibits Gastric Cancer Growth and Metastasis through HMGB1-mediated Inactivation of the PI3K/AKT/mTOR/HIF-1α Signaling Pathway.

This corrects the article on p. 439 in vol. 21, PMID: 35079445.

Orchid drug-coated balloon versus standard percutaneous transluminal angioplasty for the treatment of femoropopliteal artery disease: 12-month result of the randomized controlled trial.

PURPOSE: To assess the efficacy and safety of the Orchid drug-coated balloon (coated with paclitaxel) for the treatment of femoropopliteal artery disease versus percutaneous transluminal angioplasty in Chinese population. METHODS: This is a prospective, single center, single-blinded, randomized controlled trial that randomized (1:1) 60 patients (38 men; mean age 68.7 ± 8.8) to drug-coated balloon group (n = 30) or percutaneous transluminal angioplasty group (n = 30). The primary efficacy endpoint was primary patency of the target lesion and clinically driven target lesion revascularization (CD-TLR) at 12 months. The primary safety end point was freedom from perioperative death at 30 days and freedom from limb-related death and major amputation at 12 months. RESULTS: Baseline characteristics were similar between the two groups. Drug-coated balloon group resulted in higher primary patency (82.8% vs. 48.3%, p = 0.005) and lower CD-TLR rates (3.5% vs. 27.6%; p = 0.001) versus percutaneous transluminal angioplasty group at 12 months. The ABI was significantly higher in drug-coated balloon group than percutaneous transluminal angioplasty group (0.86 ± 0.13 vs. 0.72 ± 0.18, p = 0.025). There were no perioperative death at 30 days, no limb-related death and no major amputation at 12 months in either group. CONCLUSIONS: The randomized controlled trial showed superior treatment effect with drug-coated balloon versus percutaneous transluminal angioplasty, with remarkably higher patency and lower CD-TLR rates. The result is consistent with other study and demonstrates the safety and efficacy of the Orchid drug-coated balloon for the treatment of femoropopliteal artery disease.

Student returnees from China's COVID-19 epicenter: Spatio-temporal movement and impact of tracing.

At the initial stage of COVID-19 outbreak, tracing returnees from Wuhan - the epicenter of the disease - is a major strategy in each province of China to contain its spread. However, scholars are yet to assess the impact of tracing on individuals. Drawing upon a large-scale survey with students from four major universities in Wuhan, we investigate individual experiences with tracing activities at government and community levels and the impacts on students' socio-psychological wellbeing. Findings indicate that tracing is likely to increase the risks of privacy infringement, verbal slur, and warning at residence; and students experience moderate-to-high levels of anxiety and fear. Improved public health measures are therefore necessary to balance the twin goals of containing disease and alleviating unintended consequences of tracing.

The complete chloroplast genome sequence of Sinolimprichtia alpina var. dissecta (Apiaceae).

Sinolimprichtia alpina var. dissecta is a plant variety which is characterized from S. alpina var. alpina in possessing characteristic, highly dissected bracteoles. In the current study, we have sequenced the complete chloroplast genome of S. alpina var. dissecta using the Illumina sequencing platform. The chloroplast genome is 156,719 bp in length, consisting of a LSC region of 95,625 bp, a SSC region of 10,500 bp, and a pair of inverted repeats (IR) regions of 25,297 bp. The GC content was 37.7%. A total of 126 unique genes were identified, including 81 protein-coding genes, 37 tRNA genes and 8 rRNA genes. Phylogenetic analysis based on 28 chloroplast genomes indicates that S. alpina var. dissecta is most closely related to Pterygopleurum neurophyllum.

Cabbage defense response provoked by Trichoderma Th-LAAO.

To investigate the molecular mechanism of Trichoderma L-amino acid oxidase (Th-LAAO) in protecting and in promoting growth of cabbage infected with Botrytis cinerea, a three-way interaction system was established. Cabbage leaves treated with purified Th-LAAO significantly constrained damaged leaf area caused by B. cinerea infection. In response to Th-LAAO treatment, the expression levels of genes involved in photosynthesis, such as ribulose-1,5-bisphosphate carboxylase oxygenase, Rubisco activase, and ATP synthase increased 2.54, 2.18, and 1.41 folds, respectively. The transcription levels of sucrose transport protein 1 increased 7.6 fold. As to the expression of defense-related genes, the transcription level of ascorbate peroxidase increased 1.46 fold. On the contrary, pathogenesis-related protein 1, chitinase, ß-1,3 glucanase, and glutathione S-transferase decreased significantly. Overall, the results indicated that Th-LAAO may stimulate CO2 fixation and sucrose transport and elicit host defense responses in cabbage against B. cinerea, and this elicitation of defense response is likely to contribute to induced systemic resistance of host plant.

Randomized clinical trial of radiofrequency-induced thermotherapy combined with transilluminated powered phlebectomy versus high ligation and stripping for the treatment of lower limb varicose veins.

OBJECTIVE: The objective of this study was to evaluate the efficacy and safety of radiofrequency-induced thermotherapy (RFiTT) combined with transilluminated powered phlebectomy (TIPP) in the treatment of lower limb varicose veins (VVs) in comparison with high ligation and stripping (HLS) combined with TIPP. METHODS: The patients with lower limb VVs were randomly assigned to RFiTT combined with TIPP or HLS combined with TIPP. The primary end point was total closure rate of the great saphenous vein at 12 months. Secondary end points included Venous Clinical Severity Score and 14-item Chronic Venous Insufficiency Questionnaire score changes at 12 months and perioperative complications. RESULTS: The total closure rate of the great saphenous vein at 12 months was slightly lower in the RFiTT group (90.9% [90/99]) than in the HLS group (97.0% [98/101]) but not statistically significant (χ2 = 0.068; P = .08). Operation time, intraoperative blood loss, duration in hospital, duration in bed, and resumption of activities were statistically significantly better with RFiTT than with HLS. There were no significant differences between the groups in deep venous thrombosis, phlebitis, hematomas, pain, and infection. However, skin pigmentation and paresthesia were statistically significantly better with RFiTT than with HLS. At 12 months, both groups showed similar improvement from baseline in Venous Clinical Severity Score (1.28 ± 0.57 in the RFiTT group vs 1.33 ± 0.61 in the HLS group) and 14-item Chronic Venous Insufficiency Questionnaire score (67.32 ± 1.29 in the RFiTT group vs 67.45 ± 1.32 in the HLS group); however, neither group was superior to the other. CONCLUSIONS: RFiTT combined with TIPP is an effective treatment method for lower limb VVs and had a more satisfactory clinical outcome in surgical data, skin pigmentation, and paresthesia than HLS at the 12-month follow-up.

An Integrated Platform for Serological Detection and Vaccination of COVID-19.

Coronavirus Disease 2019 (COVID-19), caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), is an ongoing pandemic. Detection and vaccination are essential for disease control, but they are distinct and complex operations that require significant improvements. Here, we developed an integrated detection and vaccination system to greatly simplify these efforts. We constructed recombinant baculoviruses to separately display the nucleocapsid (N) and spike (S) proteins of SARS-CoV-2. Insect cells infected by the recombinant baculoviruses were used to generate a cell-based system to accurately detect patient serum. Notably, although well-recognized by our newly developed detection system in which S-displaying insect cells acted as antigen, anti-S antibodies from many patients were barely detectable by Western blot, evidencing that COVID-19 patients primarily produce conformation-dependent anti-S antibodies. Furthermore, the same baculovirus constructs can display N (N-Bac) or S (S-Bac) on the baculovirus envelope and serve as vector vaccines. Animal experiments show that S-Bac or N-Bac immunization in mice elicited a strong and specific antibody response, and S-Bac in particular stimulated effective neutralizing antibodies without the need for adjuvant. Our integrated system maintains antigen conformation and membrane structure to facilitate serum detection and antibody stimulation. Thus, compared with currently available technologies, our system represents a simplified and efficient platform for better SARS-CoV-2 detection and vaccination.

Vitexin Inhibits Gastric Cancer Growth and Metastasis through HMGB1-mediated Inactivation of the PI3K/AKT/mTOR/HIF-1α Signaling Pathway.

PURPOSE: Gastric cancer (GC) has high morbidity and mortality and is a serious threat to public health. The flavonoid compound vitexin is known to exhibit anti-tumor activity. In this study, we explored the therapeutic potential of vitexin in GC and its underlying mechanism. MATERIALS AND METHODS: The viability, migration, and invasion of GC cells were determined using MTT, scratch wound healing, and transwell assays, respectively. Target molecule expression was determined by western blotting. Tumor growth and liver metastasis were evaluated in vivo using nude mice. Protein expression in the tumor tissues was examined by immunohistochemistry. RESULTS: Vitexin inhibited GC cell viability, migration, invasion, and epithelial-mesenchymal transition (EMT) in a dose-dependent manner. Vitexin treatment led to the inactivation of phosphatidylinositol-3-kinase (PI3K)/AKT/hypoxia-inducible factor-1α (HIF-1α) pathway by repressing HMGB1 expression. Vitexin-mediated inhibition in proliferation, migration, invasion and EMT of GC cells were counteracted by hyper-activation of PI3K/AKT/HIF-1α pathway or HMGB1 overexpression. Finally, vitexin inhibited the xenograft tumor growth and liver metastasis in vivo by suppressing HMGB1 expression. CONCLUSIONS: Vitexin inhibited the malignant progression of GC in vitro and in vivo by suppressing HMGB1-mediated activation of PI3K/Akt/HIF-1α signaling pathway. Thus, vitexin may serve as a promising therapeutic agent for the treatment of GC.

Carbon emissions from the global land rush and potential mitigation.

Global drivers and carbon emissions associated with large-scale land transactions have been poorly investigated. Here we examine major factors behind such transactions (income, agricultural productivity, availability of arable land and water scarcity) and estimate potential carbon emissions under different levels of deforestation. We find that clearing lands transacted between 2000 and 2016 (36.7 Mha) could have emitted ~2.26 GtC, but constraining land clearing to historical deforestation rates would reduce emissions related to large-scale land transactions to ~0.81 GtC.

The complete chloroplast genome of Actinidia rubus (Actinidiaceae).

A complete chloroplast genome of Actinidia rubus, an endemic shrub in China, was sequenced and identified. The length of genome is 156,573 bp, and the GC content is 37.3%. This genome contains a large single copy (LSC; 88,473 bp) region, a small single copy (SSC; 20,492) region, a pair of inverted repeat (IR; 23,804) regions. A total of 113 unique genes were identified, including 78 protein-coding genes, 31 tRNA genes and 4 rRNA genes. The phylogenetic analysis based on complete chloroplast genome of 10 species showed that Actintdia eriantha was sister to A. rubus.

Investigating PM2.5 responses to other air pollutants and meteorological factors across multiple temporal scales.

It remains unclear on how PM2.5 interacts with other air pollutants and meteorological factors at different temporal scales, while such knowledge is crucial to address the air pollution issue more effectively. In this study, we explored such interaction at various temporal scales, taking the city of Nanjing, China as a case study. The ensemble empirical mode decomposition (EEMD) method was applied to decompose time series data of PM2.5, five other air pollutants, and six meteorological factors, as well as their correlations were examined at the daily and monthly scales. The study results show that the original PM2.5 concentration significantly exhibited non-linear downward trend, while the decomposed time series of PM2.5 concentration by EEMD followed daily and monthly cycles. The temporal pattern of PM10, SO2 and NO2 is synchronous with that of PM2.5. At both daily and monthly scales, PM2.5 was positively correlated with CO and negatively correlated with 24-h cumulative precipitation. At the daily scale, PM2.5 was positively correlated with O3, daily maximum and minimum temperature, and negatively correlated with atmospheric pressure, while the correlation pattern was opposite at the monthly scale.

Randomized controlled trial of orchid drug-coated balloon versus standard percutaneous transluminal angioplasty for treatment of femoropopliteal artery in-stent restenosis.

BACKGROUND: To assess the efficacy and safety of Orchid drug-coated balloon (DCB) for treatment of femoropopliteal (FP) artery in-stent restenosis (ISR) in Chinese patients. METHODS: The study is a prospective, single center, single-blinded, randomized controlled trial (RCT) that randomized (1:1) 74 patients to DCB group (N.=38) and PTA group (N.=36). The primary efficacy endpoint was primary patency of the target lesion at 12 months. Second efficacy endpoint included clinically-driven target-lesion revascularization (CD-TLR) and ABI change at 12 months. The primary safety endpoint included peri-operative death at 30 days, all-cause death, major amputation, and other major adverse events (MAEs) at 12 months. The primary functional endpoint included Walking Impairment Questionnaire (WIQ), quality-of-life measures (EQ-5D) and 6-minute walking test (6MWT). RESULTS: The DCB group had higher primary patency (87.9% vs. 51.6%; P=0.001) and lower rates of CD-TLR (6.1% vs. 35.5%; P=0.003) than the PTA group at 12 months. There were no peri-operative deaths, and no major amputations at 12 months in two groups. There were 1(2.6%) in the DCB group and 2 (5.6%) in the PTA group of all-cause deaths (P=0.524). CONCLUSIONS: Results from the study showed superior treatment effect with Orchid DCB versus PTA for the treatment of FP ISR, and without an apparent difference in safety.

Combination of Rotarex Thrombectomy and Drug-Coated Balloon for the Treatment of Femoropopliteal Artery In-Stent Restenosis.

BACKGROUND: The optimal treatment method for femoropopliteal (FP) artery in-stent restenosis (ISR) remains controversial. We assess the efficacy and safety of combination of Rotarex thrombectomy and drug-coated balloon (DCB) for the treatment of FP ISR. METHODS: From June 2016 to July 2017, 32 patients with FP ISR who underwent combination of Rotarex thrombectomy and DCB angioplasty were included in a prospective registry. The primary end point was primary patency of the target lesion defined as a peak systolic velocity ratio <2.4 documented by duplex ultrasound at 12 months without clinically driven target lesion revascularization (CD-TLR). The secondary outcome measure was the rate of major adverse limb events. The primary functional end point was assessed using the Walking Impairment Questionnaire (WIQ). RESULTS: Twenty-nine (90.6%) patients completed 12-month follow-up. Mean ankle-brachial index was 0.45 ± 0.14 at baseline and 0.84 ± 0.12 at 12 months (P < 0.05). The WIQ score was 30.45 ± 21.14 at baseline and 52.68 ± 29.75 at 12 months (P < 0.05). The Kaplan-Meier estimate of the primary patency rate at 12 months was 86.2% (25/29), and freedom from CD-TLR rate at 12 months was 89.7% (26/29). CONCLUSIONS: The data suggest that combination of Rotarex thrombectomy and DCB for treatment of FP ISR is safe and effective with satisfying primary patency rate and freedom from CD-TLR rate at 12-month follow-up.