A three-stage wavelength selection algorithm for near-infrared spectroscopy calibration.

The near-infrared spectral data is highly high dimensional and contains redundant information, it is necessary to identify the most representative characteristic wavelengths before modeling to improve model accuracy and reliability. At present, there are many methods for selecting the characteristic wavelengths of NIR spectroscopy, but the collinearity among wavelengths is still a main issue that leads to poor model effects. Therefore, this study proposes a three-stage wavelength selection algorithm (Stage III) to reduce redundancy in NIR spectral data and collinearity between wavelength variables, resulting in a simpler and more accurate predictive model. The research uses a public NIR data set of corn samples as its subject. Initially, the wavelengths with the higher correlation coefficients are chosen after calculating the relationship coefficients between every wavelength vector and the concentration vector. On this basis, the correlation coefficients between the vectors of each wavelength point are calculated, and those wavelength points with smaller correlation coefficients with other wavelength points are selected. Ultimately, the stepwise regression analysis selects the wavelengths that provide substantial value to the model as the variables for modeling, leading to the development of a multiple linear regression model. The results show that the model using the three-stage wavelength selection algorithm outperforms those using the full spectrum, Stages I and Stage II, and the coefficient of determination of the test set of the Stage III-MLR model achieved an accuracy of 0.9360. Instead of the successive projections algorithm (SPA), uninformative variable elimination (UVE), and competitive adaptive reweighted sampling (CARS), Stage III is better in the model prediction accuracy. Therefore, the three-stage wavelength selection algorithm is an effective wavelength selection algorithm that can effectively model NIR spectroscopy, reduce the collinearity between the wavelength variables, simplify the complexity of the model, and improve the prediction precision of the model.

Unveiling the Reaction Mystery Between Lithium Polysulfides and Lithium Metal Anode in Lithium-Sulfur Batteries.

Lithium-sulfur (Li-S) batteries are widely regarded as one of the most promising next-generation high-energy-density energy storage devices. However, soluble lithium polysulfides (LiPSs) corrode Li metal and deteriorate the cycling stability of Li-S batteries. Understanding the reaction mechanism between LiPSs and Li metal anode is imperative. Herein, the reaction rate and products of LiPSs with Li metal anode, the composition and structure of the as-generated solid electrolyte interphase (SEI), and the mechanism of lithium nitrate (LiNO3) additives for inhibiting the corrosion reactions are systematically unveiled. Concretely, LiPSs react with Li metal anode more rapidly than Li salt and generate a Li2S-rich SEI. The Li2S-rich SEI is highly reactive with LiPSs, which exacerbates the formation of dendritic Li and the continuous corrosion of active Li. LiNO3 functions dominantly by modulating the solvation structure of LiPSs and inherently reducing the reactivity of LiPSs, rather than the conventional understanding of LiNO3 participating in the formation of SEI. This work reveals the reaction mechanism between LiPSs and Li metal anode and inspires rational regulating of the solvation structure of LiPSs for stabilizing Li metal anode in Li-S batteries.

Evaluation of the application potential of Bdellovibrio sp. YBD-1 isolated from Yak faeces.

Studies on Bdellovibrio and like organisms (BALOs), obligate predatory bacteria, have highlighted the possibility of regulating bacteria and biofilms; however, yak-derived BALOs are yet to be reported. We aimed to characterize the BALOs isolated and identified from yak (Bos grunniens) feces and examine application potential. BALOs were isolated from healthy yak fecal samples, with Escherichia coli (ATCC 25922) as prey using the double-layer agar method, identified by transmission electron microscopy (TEM), and the specific 16S rDNA sequencing analysis. Sequencing of the 16S rDNA gene indicated that this isolate was 91% similar to the Bdellovibrio sp. NC01 reference strain and was named YBD-1. Proportion of YBD-1 lysed bacteria is 12/13. The YBD-1 showed best growth at 25-40°C, 0-0.25% (w/v) NaCl, and pH 6.5-7.5. YBD-1 significantly reduced the planktonic cells and biofilms of E.coli in co-culture compared to the E.coli group. Additionally, SEM analysis indicated that YBD-1 significantly reduced biofilm formation in E. coli. Furthermore, quantitative Real Time-polymerase chain reaction (qRT-PCR) showed that the expression of the virulence genes fim and iroN and the genes pgaABC involved in biofilm formation went down significantly. We concluded that YBD-1 may have the potential to control bacterial growth and biofilm-associated bacterial illnesses.

A Fatal Case of Cerebral Fat Embolism: A Case Report.

Fat embolism syndrome (FES) is a rare but serious multisystem syndrome that occurs after 0.9% to 2.2% of fractures, with long bone and pelvic fractures being the most common. The classic triad of FES consists of neurological impairment, respiratory insufficiency, and petechial rash, which develops 12-72 hours after the initial incident. We hereby present a case of a patient who developed persistent altered consciousness, seizures, and hypoxia secondary to a comminuted sacral fracture. Although the patient could not survive owing to multiple factors, imaging played a pivotal role in expediting the diagnostic process and aiding early management.

Kinetic Evaluation on Lithium Polysulfide in Weakly Solvating Electrolyte toward Practical Lithium-Sulfur Batteries.

Lithium-sulfur (Li-S) batteries are highly considered as next-generation energy storage techniques. Weakly solvating electrolyte with low lithium polysulfide (LiPS) solvating power promises Li anode protection and improved cycling stability. However, the cathodic LiPS kinetics is inevitably deteriorated, resulting in severe cathodic polarization and limited energy density. Herein, the LiPS kinetic degradation mechanism in weakly solvating electrolytes is disclosed to construct high-energy-density Li-S batteries. Activation polarization instead of concentration or ohmic polarization is identified as the dominant kinetic limitation, which originates from higher charge-transfer activation energy and a changed rate-determining step. To solve the kinetic issue, a titanium nitride (TiN) electrocatalyst is introduced and corresponding Li-S batteries exhibit reduced polarization, prolonged cycling lifespan, and high actual energy density of 381 Wh kg-1 in 2.5 Ah-level pouch cells. This work clarifies the LiPS reaction mechanism in protective weakly solvating electrolytes and highlights the electrocatalytic regulation strategy toward high-energy-density and long-cycling Li-S batteries.

Isolation and Identification of a Tibetan Pig Porcine Epidemic Diarrhoea Virus Strain and Its Biological Effects on IPEC-J2 Cells.

Porcine epidemic diarrhoea virus (PEDV) is a coronavirus that can cause severe watery diarrhoea in piglets, with high morbidity and mortality rates, seriously hindering the healthy development of the global swine industry. In this study, we isolated a strain of PEDV from Tibetan pigs and named it CH/GS/2022. Subsequently, we screened the apoptosis signals of PEDV-infected IPEC-J2 cells and studied the correlation between apoptosis signals and cell apoptosis. The results showed that different infections of PEDV induced different degrees of apoptosis in cells, and PEDV-induced cell apoptosis was dose-dependent. We then detected the expression of the p53, p38, JNK, Bax, and Bcl-2 genes in the apoptosis signal pathway. The results showed that 24 h after PEDV infection, the expression of the p53, p38, JNK, and Bax genes in IPEC-J2 cells increased significantly, while the expression of the Bcl-2 gene decreased significantly (p < 0.05). Subsequently, we used Western blot to detect the protein levels of these five genes, and the results showed that PEDV infection upregulated the expression of p53, p38, JNK, and Bax proteins (p < 0.05) while downregulating the expression of Bcl-2 protein (p < 0.05). Thus, it was initially inferred that PEDV infection could regulate cell apoptosis by activating the p53, p38, and JNK signalling pathways. Finally, we further investigated the apoptosis of the cells through the use of inhibitors. The results indicated that the p53 inhibitor Pifithrin-α has a significant inhibitory effect on the expression of the p53 protein after PEDV infection and can reverse the expression levels of Bax and Bcl-2 proteins. This suggested that p53 is involved in PEDV-induced cell apoptosis. Similarly, the p38 MAPK inhibitor SB203580 has an inhibitory effect on the expression of the p38 protein and can reverse the expression levels of Bax and Bcl-2 proteins. This suggested that p38 is also involved in PEDV-induced cell apoptosis. On the other hand, the JNK inhibitor SP600125 has no inhibitory effect on the expression of the JNK protein after PEDV infection, but the expression levels of Bax and Bcl-2 proteins have changed. Furthermore, it is noteworthy that SP600125 can inhibit the activity of apoptotic proteins but not their levels, resulting in reduced cell apoptosis. These preliminary results indicated that JNK may be involved in PEDV-induced IPEC-J2 cell apoptosis.

Versatile Polymerization-Induced Emission Polymers from Barbier Polymerization of Cinnamic Esters with Tunable Emission.

Cinnamic ester is a common and abundant chemical substance, which can be extracted from natural plants. Compared with traditional esters, cinnamic ester contains α,ß-unsaturated carbonyl structure with multiple reactive sites, resulting in more abundant reactivities and chemical structures. Here, a versatile polymerization-induced emission (PIE) is successfully demonstrated through Barbier polymerization of cinnamic ester. Attributed to its abundant reactivities of α,ß-unsaturated carbonyl structure, Barbier polymerization of cinnamic esters with different organodihalides gives polyalcohol and polyketone via 1,2-addition and 1,4-addition, respectively, which is also confirmed by small molecular model reactions. Meanwhile, these organodihalides dependant polyalcohol and polyketone exhibit different non-traditional intrinsic luminescence (NTIL) from aggregation-induced emission (AIE) type to aggregation-caused quenching (ACQ) type, where novel PIE luminogens (PIEgens) are revealed. Further potential applications in explosive detection are carried out, where it achieves TNT detection sensitivity at ppm level in solution and ng level on the test paper. This work therefore expands the structure and functionality libraries of monomer, polymer and NTIL, which might cause inspirations to different fields including polymer chemistry, NTIL, AIE and PIE.

Clickable Polymerization-Induced Emission Luminogens Toward Color-Tunable Modification of Non-Traditional Intrinsic Luminescent Polymers.

Non-traditional intrinsic luminescent (NTIL) polymer is an emerging field, and its color-tunable modification is highly desirable but still rarely investigated. Here, a click chemistry approach for the color-tunable modifications of NTIL polymers by introducing clickable polymerization-induced emission luminogen (PIEgen), is demonstrated. Through Cu-catalyzed azide-alkyne cycloaddition click chemistry, a series of PIEgens is successful prepared, which is further polymerized via reversible addition-fragmentation chain transfer (RAFT) polymerization. Interestingly, after clickable modification, these monomers are nonemissive in both solution and aggregation states; while, the corresponding polymers exhibit intriguing aggregation-induced emission (AIE) characteristics, confirming their PIEgen characteristics. By varying alkynyl substitutions, color-tunable NTIL polymers are achieved with emission wavelength varying from 448 to 498 nm, revealing a series of PIEgens and verifying the importance of modification of NTIL polymers. Further luminescence energy transfer application is carried out as well. This work therefore designs a series of clickable PIEgens and opens a new avenue for the modification of NTIL polymers via click chemistry, which may cause inspirations to the research fields including luminescent polymer, NTIL, click chemistry, AIE and modification.

Construction methods and application of assembloids / 中国组织工程研究

BACKGROUND:In recent years,many studies have confirmed that assembloids can make up for the shortcomings of organoids,which cannot fully reproduce the interaction between cell and cell and between cell and matrix.Since the assembloids construction methods are in the early stage of development,there is no unified standard. OBJECTIVE:To review the current construction methods,applications,advantages,and disadvantages of assembloids,guide the development and improvement of vitro cell models. METHODS:PubMed,CNKI,and WanFang databases were searched with English search terms"assembloids,organoids,tumor microenvironment,organoids AND assemble,organoids AND microenvironment"and Chinese search terms"assembloids,organoids,tumor microenvironment,organoid reorganization,multicellular model".Totally 94 articles were screened out for review after excluding irrelevant articles and deduplication. RESULTS AND CONCLUSION:(1)According to the different sources of cells,the construction of assembloids can be divided into three methods:self-assembly,direct-assembly,and mixed-assembly.According to the differences of cell culture methods,it can be divided into suspension culture method,matrix culture method,organ chip culture method,and 3D bio-printing.(2)The process of self-assembly covers early stages of cell and tissue development,so it has broad prospects in the fields of organ development and developmental disorders.The function of differentiated mature cells is relatively perfect,and the assembloids directly assembled by them have more potential in the study of functional disorders and cell-damaging diseases.Self-assembly may be better in organ transplantation,and direct-assembly will be more suitable for the repair of tissue damage.Mixed-assembly combines the advantages of the former two and is mostly used to explore the physiological and pathological mechanisms of cells in the microenvironment,as well as drug screening.(3)Although different assembloids have their own advantages,they all face the problem of imperfect vasculature system,then,each method has its own limitations,for example,the degree of cell differentiation in self-assembly assembloids may still be different from that in vivo,and the fixed cell types in direct-assembly models cannot simulate complex microenvironments in vivo.These are urgent problems to be solved.(4)In the future,with the continuous improvement of assembloids culture technology,scientists can assemble biomimetic organoids with more complex tissues in vitro,providing infinitely realistic models for the study of physiological and pathological processes of human tissue and organ.

Assessment of respiratory protection competency of staff in healthcare facilities / 中国感染控制杂志

Objective To understand the respiratory protection competency of staff in hospitals.Methods Staff from six hospitals of different levels and characteristics in Beijing were selected,including doctors,nurses,medical technicians,and servicers,to conduct knowledge assessment on respiratory protection competency.According to exposure risks of respiratory infectious diseases,based on actual cases and daily work scenarios,content of respira-tory protection competency assessment was designed from three aspects:identification of respiratory infectious di-seases,transmission routes and corresponding protection requirements,as well as correct selection and use of masks.The assessment included 6,6,and 8 knowledge points respectively,with 20 knowledge points in total,all of which were choice questions.For multiple-choice questions,full marks,partial marks,and no mark were given respective-ly if all options were correct,partial options were correct and without incorrect options,and partial options were correct but with incorrect options.Difficulty and discrimination analyses on question of each knowledge point was conducted based on classical test theory.Results The respiratory protection competency knowledge assessment for 326 staff members at different risk levels in 6 hospitals showed that concerning the 20 knowledge points,more than 60％participants got full marks for 6 points,while the proportion of full marks for other questions was relatively low.Less than 10％participants got full marks for the following 5 knowledge points:types of airborne diseases,types of droplet-borne diseases,conventional measures for the prevention and control of healthcare-associated infec-tion with respiratory infectious diseases,indications for wearing respirators,and indications for wearing medical protective masks.Among the 20 knowledge questions,5,1,and 14 questions were relatively easy,medium,and difficult,respectively;6,1,4,and 9 questions were with discrimination levels of ≥0.4,0.30-0.39,0.20-0.29,and ≤0.19,respectively.Conclusion There is still much room for hospital staff to improve their respiratory protection competency,especially in the recognition of diseases with different transmission routes and the indications for wearing different types of masks.

Current status of neonatal skin disinfectant use in 71 medical institutions in China / 中国感染控制杂志

Objective To understand the application of skin disinfectant in neonatal intensive care units(NICUs)nationwide.Methods From April to May 2023,application of skin disinfectant in 93 NICUs nationwide was sur-veyed with convenience sampling method by a self-designed questionnaire.Questionnaire contents included types of disinfectant,disinfection tools,cleaning and disinfection frequency,disinfectant drying status,removal of disinfec-tant,and adverse reactions caused by disinfectant.Results A total of 93 nursing units in 71 medical institutions from 25 provinces/municipalities were included in this study.In NICUs,three most commonly used disinfectants were ethanol(79.57％),iodophor(74.19％),and anerdian(62.37％).In nursing units for neonates＜2 months of age,chlorhexidine was prohibited in 28 units(30.11％),used with caution in 23 units(24.73％),allowed in 9 units(9.68％),and there was no unified requirement in 33 units(35.48％).When using ethanol,staff only wiped once in 13(17.57％)nursing units.In some nursing units,there was no unified requirements on the wiping fre-quency of disinfectant.As for the removal of residual iodine,saline was used in 29(42.03％)nursing units,ethanol in 8(11.59％),and 19(27.54％)did not have unified requirements.The adverse reactions of disinfectant mainly included rash and contact dermatitis.Disinfectants that caused adverse reactions included ethanol,iodophor,aner-dian,and chlorhexidine.Conclusion In clinical practice,unified standards for the use of neonatal skin disinfectant remain absent.Selection and use of neonatal skin disinfectant vary considerably.Neonatal skin disinfectants have common adverse reactions.It is necessary to strengthen the training of health care workers on the standardized use of disinfectant,as well as carry out large-scale and rigorous randomized controlled trial designs to provide scientific basis for the correct selection of disinfectant.

Implementation of surveillance,prevention and control of healthcare-asso-ciated infection in maternal and child healthcare institutions:A nation-wide investigation report / 中国感染控制杂志

Objective To investigate the implementation of surveillance,prevention and control measures for healthcare-associated infection(HAI)in maternal and child healthcare(MCH)institutions,and provide policy evi-dence for optimizing HAI prevention and control in MCH institutions.Methods Stratified sampling was conducted among the MCH institutions at provincial,municipal and county levels in 8 provinces/autonomous regions.A uni-fied questionnaire was designed and the online survey was conducted through"Questionnaire Star".Results The data from 123 MCH institutions were included in the analysis.90.24％of the MCH institutions carried out compre-hensive surveillance on HAI.The ratios of MCH institutions which implemented targeted surveillance on HAI in neonatal intensive care unit(NICU),surgical site infection,multidrug-resistant organisms(MDROs)and HAI in intensive care units(non-NICU excluded)were 89.66％,85.96％,80.77％,and 74.19％,respectively.51.22％MCH institutions adopted information surveillance system on HAI cases.94.31％MCH institutions carried out surveillance on hand hygiene compliance.Over 90％MCH institutions carried out surveillance on environment hy-giene in high-risk departments.71.54％MCH institutions conducted centralized cleaning,disinfection,sterilization and supply for reusable medical instruments in the central sterile supply department(CSSD).Over 90％MCH insti-tutions established three-level pre-examination triage systems.86.18％set up transitional wards.MCH institutions generally adopted a management model with established effective communication,full appointment visits,and sepa-rate visits for special medical groups,such as registered pregnant women,high-risk newborns,healthcare groups,and long-term rehabilitation patients.However,the ratio of institutions conducting on-line follow-up visits was less than 50％.Conclusion MCH institutions have generally carried out comprehensive and targeted surveillance on HAI.Information surveillance need to be facilitated.Hand hygiene and environmental hygiene surveillance has been popularized to a certain extent at all levels of MCH institutions.The cleaning,disinfection,sterilization,and supply processes of reusable medical devices in a few MCH institutions are not standardized.Special medical populations get effective management.On-line healthcare is to be further promoted.

Myeloperoxidase, carnitine, and derivatives of reactive oxidative metabolites in heart failure with preserved versus reduced ejection fraction: A meta-analysis.

BACKGROUND: Understanding the pathophysiology of heart failure (HF) with preserved ejection fraction (HFpEF) continues to be challenging. Several inflammatory and metabolic biomarkers have recently been suggested to be involved in HFpEF. OBJECTIVES: The purpose of this review was to synthesize the evidence on non-traditional biomarkers from metabolomic studies that may distinguish HFpEF from heart failure with reduced ejection fraction (HFrEF) and controls without HF. METHODS: A systematic search was conducted using Medline and PubMed with search terms such as "HFpEF" and "metabolomics", and a meta-analysis was conducted. RESULTS: Myeloperoxidase (MPO) levels were significantly (p < 0.001) higher in HFpEF than controls without HF, but comparable (p = 0.838) between HFpEF and HFrEF. Carnitine levels were significantly (p < 0.0001) higher in HFrEF than HFpEF, but comparable (p = 0.443) between HFpEF and controls without HF. Derivatives of reactive oxidative metabolites (DROMs) were not significantly (p = 0.575) higher in HFpEF than controls without HF. CONCLUSION: These data suggest that MPO is operative in HFpEF and HFrEF and may be a biomarker for HF. Furthermore, circulating carnitine levels may distinguish HFrEF from HFpEF.