TiO2 Electron Transport Layer with p-n Homojunctions for Efficient and Stable Perovskite Solar Cells.

Low-temperature processed electron transport layer (ETL) of TiO2 that is widely used in planar perovskite solar cells (PSCs) has inherent low carrier mobility, resulting in insufficient photogenerated electron transport and thus recombination loss at buried interface. Herein, we demonstrate an effective strategy of laser embedding of p-n homojunctions in the TiO2 ETL to accelerate electron transport in PSCs, through localized build-in electric fields that enables boosted electron mobility by two orders of magnitude. Such embedding is found significantly helpful for not only the enhanced crystallization quality of TiO2 ETL, but the fabrication of perovskite films with larger-grain and the less-trap-states. The embedded p-n homojunction enables also the modulation of interfacial energy level between perovskite layers and ETLs, favoring for the reduced voltage deficit of PSCs. Benefiting from these merits, the formamidinium lead iodide (FAPbI3) PSCs employing such ETLs deliver a champion efficiency of 25.50%, along with much-improved device stability under harsh conditions, i.e., maintain over 95% of their initial efficiency after operation at maximum power point under continuous heat and illumination for 500 h, as well as mixed-cation PSCs with a champion efficiency of 22.02% and over 3000 h of ambient storage under humidity stability of 40%. Present study offers new possibilities of regulating charge transport layers via p-n homojunction embedding for high performance optoelectronics.

Dopamine Sulfonate Ligand-Assisted TiO2 Deposition Enabling Highly Efficient and Stable Perovskite Solar Cells.

The metal oxide electron transport layers (ETLs) with flat morphology and high electrical quality are essential to manufacture highly efficient perovskite solar cells (PSCs), in which the regulation of the metal oxide deposition process plays a crucial role. Herein, a judiciously designed dopamine sulfonate (DS) ligand-assisted deposition of titanium dioxide (TiO2) films approach is implemented based on electrostatic repulsion and steric hindrance of assembled ligands to improve colloidal nanoparticles dispersity in precursor and effectively inhibit their aggregation, which could enable obtaining smooth topography of TiO2 films and initiating growth of top high-quality perovskite films. Furthermore, sulfonate bridges bonded on the perovskite buried layer that is beneficial to form better buried interface contact and accelerate electron extraction. As a result, the PSCs employing DS/TiO2 ETLs exhibit the best power conversion efficiency of 24.53% with impressive storage stability and operation stability, i.e., remaining more than 88% of their initial efficiency upon storage N2 glovebox without encapsulation over 4000 h, and the efficiency does not attenuate significantly under maximum power point for 60 h.

High-Performance Thermoelectric Fibers from Metal-Backboned Polymers for Body-Temperature Wearable Power Devices.

Metal-backboned polymers (MBPs), with a unique backbone consisting of bonded metal atoms, are promising for optic, electric, magnetic, and thermoelectric fields. However, the application of MBP remains relatively understudied. Here, we develop a shear-induced orientation method to construct a flexible nickel-backboned polymer/carbon nanotube (NBP/CNT) thermoelectric composite fiber. It demonstrated a power factor of 719.48 µW ⋅m-1 K-2, which is ca. 3.5 times as high as the bare CNT fiber. Remarkably, with the regulation of carrier mobility and carrier concentration of NBP, the composite fiber further showed simultaneous increases in electrical conductivity and Seebeck coefficient in comparison to the bare CNT fiber. The NBP/CNT fiber can be integrated into fabrics to harvest thermal energy of human body to generate an output voltage of 3.09 mV at a temperature difference of 8 K. This research opens a new avenue for the development of MBPs in power supply.

Preparation of Hydrophilic Hyper-Cross-Linked Polystyrene Nanospheres with Antibacterial for Improved Water Lubrication Performance.

The present study utilizes styrene as a raw material to prepare hyper-cross-linked polystyrene nanospheres (HPSs) through the Friedel-Crafts reaction, establishing stable covalent bond structures within the polymer chains. The hydrophilic polystyrene nanospheres─TMA@SHPSs were successfully synthesized via sulfonation and ion exchange reactions, demonstrating exceptional properties in reducing friction and wear. Compared with pure water, the addition of 4.0 wt % TMA@SHPSs results in a 62.2% reduction in the friction coefficient, accompanied by a significant decrease to 1.17 × 105 µm3 in wear volume. The results demonstrate that TMA@SHPSs, as water-based lubrication additives, generate composite protective films (tribo-chemical protective films and physical protective films) during the friction process, which effectively prevents direct contact between the friction pairs and achieves remarkable antifriction and antiwear effects. The results of the antimicrobial activity test indicate that TMA@SHPSs demonstrate exceptional antibacterial efficacy due to the bacteriostatic effect induced by hydration and the bactericidal properties of quaternary ammonium cations.

Decreased Electrically and Increased Ionically Conducting Scaffolds for Long-Life, High-Rate and Deep-Capacity Lithium-Metal Anodes.

Lithium (Li) metal batteries are deemed as promising next-generation power solutions but are hindered by the uncontrolled dendrite growth and infinite volume change of Li anodes. The extensively studied 3D scaffolds as solutions generally lead to undesired "top-growth" of Li due to their high electrical conductivity and the lack of ion-transporting pathways. Here, by reducing electrical conductivity and increasing the ionic conductivity of the scaffold, the deposition spot of Li to the bottom of the scaffold can be regulated, thus resulting in a safe bottom-up plating mode of the Li and dendrite-free Li deposition. The resulting symmetrical cells with these scaffolds, despite with a limited pre-plated Li capacity of 5 mAh cm-2, exhibit ultra-stable Li plating/stripping for over 1 year (11 000 h) at a high current density of 3 mA cm-2 and a high areal capacity of 3 mAh cm-2. Moreover, the full cells with these scaffolds further demonstrate high cycling stability under challenging conditions, including high cathode loading of 21.6 mg cm-2, low negative-to-positive ratio of 1.6, and limited electrolyte-to-capacity ratio of 4.2 g Ah-1.

Antimicrobial resistance and genomic investigation of Salmonella isolated from retail foods in Guizhou, China.

Introduction: Salmonella is a major foodborne pathogen worldwide that causes severe morbidity and mortality. It is mainly caused by consuming contaminated food, with retail food considered the primary source. Methods: In Guizhou, China, 102 Salmonella strains isolated from 2016 to 2021 underwent phenotypic antimicrobial resistance testing and whole-genome sequencing (WGS) to understand Salmonella diversity, including serotypes, sequencing types (STs), antimicrobial genes, virulence genes, plasmid types, multi-locus sequence types (MLST), and core genome MLST (cgMLST). Results and discussion: S.Typhimurium was the dominant serotype, and O:4(B) was the leading serogroup. The most prevalent genotype was ST40. Phenotypic antimicrobial resistance identified 66.7% of the sampled isolates as multi-drug resistant (MDR). S.Enteritidis (n = 7), S.Typhimurium (n = 1), S.Indiana (n = 1), S.Kentucky (n = 1), S.Uganda (n = 1), all of which were MDR, were resistant to Colistin. Resistance rates varied significantly across different strains and food types, particularly meat products exhibiting higher resistance. Notably, significant increases in resistance were observed from 2016 to 2021 for the following: ≥ 1 resistant (P = 0.001), MDR (P = 0.001), ampicillin (P = 0.001), tetracycline (P < 0.001), chloramphenicol (P = 0.030), and trimethoprim/sulfamethoxazole (P = 0.003). The marked escalation in drug resistance over the recent years, coupled with the varying resistance rates among food sources, underscores the growing public health concern. Our findings highlight the need for a coordinated approach to effectively monitor and respond to Salmonella infections in Guizhou, China.

Reduction in Interferon-Stimulated Genes Contributes to High-Yield Production of Influenza Virus in Suspension MDCK Cells.

Compared with the traditional vaccine produced in embryonated chicken eggs, cell-based manufacturing represented by the Madin-Darby canine kidney (MDCK) cell line has a larger production scale and reduces the risk of egg shortage in a pandemic. Establishing a culture system that enables high production of the influenza virus is a key issue in influenza vaccine production. Here, a serum-free suspension culture of MDCK (sMDCK) cells was obtained from adherent MDCK (aMDCK) cells by direct adaptation. Viral infection experiments showed that viral yields of influenza A/B virus in sMDCK cells were higher than in aMDCK cells. Transcriptome analysis revealed that numerous interferon-stimulated genes (ISGs) exhibited reduced expression in sMDCK cells. To further clarify the mechanism of high viral production in sMDCK cells, we demonstrated the antiviral role of RIG-I and IFIT3 in MDCK cells by knockdown and overexpression experiments. Furthermore, suppression of the JAK/STAT pathway enhances the viral accumulation in aMDCK cells instead of sMDCK cells, suggesting the reduction in the JAK/STAT pathway and ISGs promotes viral replication in sMDCK cells. Taken together, we elucidate the relationship between the host innate immune response and the high viral productive property of sMDCK cells, which helps optimize cell production processes and supports the production of cell-based influenza vaccines.

Characterization of cellular responses and cell lysis to elevated hydrodynamic stress from benchtop perfusion bioreactors.

The effective design of perfusion cell culture is currently challenging regarding balancing the operating parameters associated with the hydrodynamic conditions due to increased system complexity. To address this issue, cellular responses of an industrial CHO cell line to different types of hydrodynamic stress in benchtop perfusion bioreactors originating from agitation, sparging, and hollow fibers (HF) in the cell retention devices were systematically investigated here with the analysis of cell lysis. It was found that cell lysis was very common and most associated with the sparging stress, followed by the HF and lastly the agitation, consequently heavily impacting the estimation of process descriptors related to biomass. The results indicated that the agitation stress led to a reduced cell growth with a shift toward a more productive phenotype, suggesting an energy redirection from biomass formation to product synthesis, whereas the sparging stress had a small impact on the intracellular metabolic flux distribution but increased the cell death rate drastically. For HF stress, a similar cell maintenance profile was found as the sparging while the activity of glycolysis and the TCA cycle was significantly impeded, potentially leading to the lack of energy and thus a substantial decrease in cell-specific productivity. Moreover, a novel concept of volume average shear stress was developed to further understand the relations of different types of stress and the observed responses for an improved insight for the perfusion cell culture.

Case Report: Clinical and Pathological Findings of Tuberculous Gumma: A Case Report and Literature Review.

Tuberculous gumma (TG) is a rare type of cutaneous tuberculosis thought to occur as a result of the hematogenous spread of Mycobacterium tuberculosis, which is more common in immunosuppressed individuals. An 8-year-old boy presented with a 2-month history of multiple indolent enlarging ulcerated nodules on his left upper extremity. He had a past medical history of bacille Calmette-Guerin vaccine induced lupus vulgaris. Skin biopsy of the nodules showed granulomas and neutrophil-dominated purulent inflammation. Ziehl-Neelsen staining was negative, and the cultures were positive for M. tuberculosis. Furthermore, the M. tuberculosis complex was identified using metagenomic next-generation sequencing. Standard antitubercular therapy was started at full doses, and the skin lesions had significantly improved 3 months later. Here we review the literature since 2000 and describe the clinical and pathological features of TG.

Tuning capsid formation dynamics in recombinant adeno-associated virus producing synthetic cell lines to enhance full particle productivity.

Recombinant adeno-associated virus (rAAV) is widely used as an in vivo delivery vector for gene therapy. It is used in a very large dose, and the large quantities required for broad applications present manufacturing challenges. We have developed a synthetic biology platform of constructing cell lines integrated with essential viral genes which can be induced to produce rAAV without plasmid transfection or virus transduction. Through iterative design-construct-characterization cycles, we have showcased the potential of this synthetic cell production system. Systems characterization of the dynamics of viral transcripts and proteins as well as virus assembly and packaging revealed that the expression level and balance of viral genome and capsid protein are keys to not only the productivity but also the full particle content, an important product quality attribute. Boosting cap gene expression by sequential transfection and integration of multiple copies of the cap gene elevated the rAAV titer to levels on a par with traditional plasmid transfection and virus infection. However, overexpression of the cap gene shifted the balance and kinetics of the genome and capsid. We independently tuned the dynamics of genome amplification and capsid protein synthesis by modulating the induction concentration as well as the time profile, and significantly enhanced full particle content while maintaining a high productivity. This strategy of constructing an inducible stable producer cell line is readily adaptable to rAAV vectors of different serotypes and payloads. It can greatly facilitate scalable production of gene therapy vectors.

Mechanochemical Synthesis of Thiadiazole Functionalized COF as Oil-Based Lubricant Additive for Reducing Friction and Wear.

In this work, the functionalized covalent organic framework (COF) was prepared via a convenient ball milling process. The aldehyde group terminated COF-F reacted with amino thiadiazole in the ball milling jar under mechanical forces; hence, the thiadiazole functionalized COF-F was obtained and denoted as Thdz@COF-F. The as-prepared Thdz@COF-F serves as an oil-based lubricant additive and exhibits remarkable tribological properties, which can reduce the average friction coefficient of base oil from 0.169 to 0.102 and decrease the wear volume by 87.0%. The antifriction and antiwear performances are mainly due to the repairing effect of Thdz@COF-F nanoparticles and the protective tribo-film that averts the direct contact of friction pairs. In addition, through the ball milling method, triazole and thiazole functionalized COF-F were also prepared and represented good lubrication performance, demonstrating the feasibility of this mechanochemical synthesis method for functionalized COFs.

Pulsed Laser Manufactured Heteroatom Doped Carbon Dots via Heterocyclic Aromatic Hydrocarbons for Improved Tribology Performance.

Traditional laser-assisted method (top-down synthesis strategy) is applied in the preparation of carbon dots (CDs) by cutting larger carbon materials, which requires harsh conditions, and the size distribution of the CDs is seldom monodisperse. In this work, heteroatom-doped CDs, represented by N,S co-doped CDs (N,S-CDs), can be prepared successfully by pulsed laser irradiation of heterocyclic aromatic hydrocarbons-based small molecule compound solution. The friction coefficient (COF) of base oil PAO decreases from 0.650 to 0.093, and the wear volume reduces by 92.0% accompanied by 1 wt.% N,S-CDs addition, while the load-bearing capacity is improved from 100 to 950 N. The excellent lubrication performance is mainly attributed to the formation of a robust tribofilm via a tribochemical reaction between N,S-CDs and friction pairs, and the N,S-CDs can play a mending effect and polishing effect for worn surfaces. Furthermore, the lubricant containing heteroatom doped CDs are capable of being prepared in situ via pulsed laser irradiation of heterocyclic aromatic hydrocarbons in base oil, which can avoid the redispersed problem of nano-additive in base oil to maintain long-term dispersion, with COF of 0.103 and low wear volume ≈1.99 × 105 µm3 (76.9% reduction) even after standing for 9 months.

Carbon Dots with Spatially-Mediated-N/S-Co-Doping Enabling One-Year Stable Lubricant with Oil Leakage Detection Capability.

The dispersion stability of nano-lubricating additives is crucial for the shelf life of lubricant and its practical applications. Nitrogen-sulfur co-doped carbon dots (N,S@CDs) via a one-step hydrothermal method with nitropyrene and thiourea as raw materials are hereby presented. The N and S elements are selectively distributed throughout the entire carbon skeleton with a doping amount of 22.6 at%. The as-synthesized N,S@CDs exhibit excellent dispersion stability in PEG200 and maintain stability for over one year. The experiment results indicate that N,S@CDs significantly improve the anti-wear and friction reduction properties of PEG200, while the friction coefficient is reduced from 0.25 to 0.09 with 1.5 wt% N,S@CDs addition, and the wear volume, depth, and width are reduced by 68%, 52%, and 57%, respectively. The good lubrication performance is attributed to N,S@CDs excellent dispersion stability, enhanced filling and polishing effects, and complex tribochemical reactions caused by heteroatom doping to form a stable protective film on the worn surface. Furthermore, the as-prepared N,S@CDs exhibit intrinsic fluorescence intensity in PEG200 with the photoluminescence quantum yield (PLQY) of 12.5% and remain fluorescent stable during the long-term friction process, therefore the N,S@CDs have a potential application prospect in non-destructive detection of oil leakage via fluorescence labeling method.

The role of gastrin 17 and pepsinogen I:pepsinogen II ratio in pathological diagnosis and endoscopic selection in gastritis patients.

BACKGROUND: The noninvasive serum markers pepsinogen I (PGI), pepsinogen II (PGII), gastrin-17 (G17), and PGI:PGII ratio (PGR) have recently been proposed as a new tool for predicting various gastric pathologies. METHODS: A total of 83 gastritis patients confirmed by gastroscopy were enrolled, with 78 undergoing concurrent colonoscopies. The control group included 99 healthy subjects. Enzyme-linked immunosorbent assay was used to detect PGI, PGII, G17, and PGR. The performance of serological analysis for detecting gastritis pathology was evaluated using receiver operating characteristic (ROC) curves. RESULTS: The G17 and PGII levels increased significantly (P < .001), whereas PGR levels decreased (P = .001) in the gastritis group. The ROC analysis revealed that PGR had a sensitivity and specificity of 70.83% and 86.67%, respectively, in predicting Helicobacter pylori-infected gastritis and a sensitivity and specificity of 88% and 65.52%, respectively, in predicting active gastritis. The G17 levels were significantly elevated in gastritis patients undergoing concurrent colonoscopies (P < .05). CONCLUSION: Pepsinogen I:pepsinogen II ratio was found to be a useful predictor of active gastritis and H pylori-infected gastritis. Furthermore, G17 was found to be closely related to pathological conditions found by colonoscopy and may provide recommendations for whether gastritis patients should undergo a concurrent colonoscopy.

Development of a novel tyrosine-based selection system for generation of recombinant Chinese hamster ovary cells.

Efficiently expanding Chinese hamster ovary (CHO) cells, which serve as the primary host cells for recombinant protein production, have gained increasing industrial significance. A significant hurdle in stable cell line development is the low efficiency of the target gene integrated into the host genome, implying the necessity for an effective screening and selection procedure to separate these stable cells. In this study, the genes of phenylalanine hydroxylase (PAH) and pterin 4 alpha carbinolamine dehydratase 1 (PCBD1), which are key enzymes in the tyrosine synthesis pathway, were utilized as selection markers and transduced into host cells together with the target genes. This research investigated the enrichment effect of this system and advanced further in understanding its benefits for cell line development and rCHO cell culture. A novel tyrosine-based selection system that only used PCBD1 as a selection marker was designed to promote the enrichment effect. Post 9 days of starvation, positive transductants in the cell pool approached 100%. Applied the novel tyrosine-based selection system, rCHO cells expressing E2 protein were generated and named CHO TS cells. It could continue to grow, and the yield of E2 achieved 95.95 mg/L in a tyrosine-free and chemically-defined (CD) medium. Herein, we introduced an alternative to antibiotic-based selections for the establishment of CHO cell lines and provided useful insights for the design and development of CD medium.

Hydrogen bond unlocking-driven pore structure control for shifting multi-component gas separation function.

Purification of ethylene (C2H4) as the most extensive and output chemical, from complex multi-components is of great significance but highly challenging. Herein we demonstrate that precise pore structure tuning by controlling the network hydrogen bonds in two highly-related porous coordination networks can shift the efficient C2H4 separation function from C2H2/C2H4/C2H6 ternary mixture to CO2/C2H2/C2H4/C2H6 quaternary mixture system. Single-crystal X-ray diffraction revealed that the different amino groups on the triazolate ligands resulted in the change of the hydrogen bonding in the host network, which led to changes in the pore shape and pore chemistry. Gas adsorption isotherms, adsorption kinetics and gas-loaded crystal structure analysis indicated that the coordination network Zn-fa-atz (2) weakened the affinity for three C2 hydrocarbons synchronously including C2H4 but enhanced the CO2 adsorption due to the optimized CO2-host interaction and the faster CO2 diffusion, leading to effective C2H4 production from the CO2/C2H2/C2H4/C2H6 mixture in one step based on the experimental and simulated breakthrough data. Moreover, it can be shaped into spherical pellets with maintained porosity and separation performance.

Synthetic Cell Lines for Inducible Packaging of Influenza A Virus.

Influenza A virus (IAV) is a negative-sense RNA virus that causes seasonal infections and periodic pandemics, inflicting huge economic and human costs on society. The current production of influenza virus for vaccines is initiated by generating a seed virus through the transfection of multiple plasmids in HEK293 cells followed by the infection of seed viruses into embryonated chicken eggs or cultured mammalian cells. We took a system design and synthetic biology approach to engineer cell lines that can be induced to produce all viral components except hemagglutinin (HA) and neuraminidase (NA), which are the antigens that specify the variants of IAV. Upon the transfection of HA and NA, the cell line can produce infectious IAV particles. RNA-Seq transcriptome analysis revealed inefficient synthesis of viral RNA and upregulated expression of genes involved in host response to viral infection as potential limiting factors and offered possible targets for enhancing the productivity of the synthetic cell line. Overall, we showed for the first time that it was possible to create packaging cell lines for the production of a cytopathic negative-sense RNA virus. The approach allows for the exploitation of altered kinetics of the synthesis of viral components and offers a new method for manufacturing viral vaccines.

Hybrid Carbon Nanospheres with Encapsulated (Bi)Metallic Nanocrystals as Lubricant Additives for Antiwear and Friction Reduction.

Herein, the novel core-shell organo-inorganic hybrid carbon nanospheres with encapsulated ultrafine bimetal nanocrystals were successfully prepared by a one-pot domino drive synthesis combined with postcarbonization. The excellent properties of the metals such as high strength and thermal conductivity are retained, and the poor dispersion of the metal in the oil could be improved by encapsulating the metal in organic-inorganic hybrid carbon nanospheres. The vanadium and wolframium nanocrystals embedded in nitrogen-doped carbon nanospheres (V/W@NCNs) manifested remarkable oil dispersity on account of the lipophilic organic phase of the carbon shell. It is worth noting that the as-obtained V/W@NCNs display better tribological properties compared with the base oil, such as a higher extreme pressure of 1250 N, a lower friction coefficient of about 0.09, and a significant reduction in wear volume of 91.5%, which are attributed to the robust protective film that was formed on the surface of the friction pair through mechanical deposition and physical and tribochemical reaction during the friction process.

Risk of HCC decreases in HBV-related patients with cirrhosis acquired recompensation: A retrospective study based on Baveno VII criteria.

BACKGROUND: Antiviral therapy improves the clinical outcomes of patients with HBV-related cirrhosis. In this study, we aimed to evaluate the incidence rate of HCC in patients with HBV-related recompensated, compensated, or decompensated cirrhosis based on the latest Baveno VII criteria. METHODS: In this two-center retrospective study, HBV-related patients with cirrhosis were enrolled and treated with first-line nucleos(t)ide analogues therapy for at least 12 months. Participants were classified into 3 groups: (1) compensated group, (2) decompensated group, or (3) recompensated group according to Baveno VII criteria. Multivariate regression models and propensity score matching were used to identify the predictors of HCC. RESULTS: Of the 404 patients recruited, during a median follow-up of 44.5 months (interquartile range 26.8, 57.0 months), 233 (57.7%), 100 (24.8%), and 71(17.6%) patients had compensated, recompensated, and decompensated cirrhosis. In total, 38 developed HCC. The cumulative incidence of HCC development at 2, 4, and 6 years was 1.3%, 5.4%, and 20.0% in the compensated group, 1.2%, 5.2%, and 24.5% in the recompensated group, and 2.1%, 23.6%, and 41.8% in the decompensated group, respectively. In the multivariate Cox regression model, compared with the recompensated group, the decompensated group had a significant increased risk for the development of HCC (aHR 2.55; 95% CI: 1.240-5.240; p = 0.027), while the compensated group had similar HCC risk for the development of HCC (aHR 1.41; 95% CI: 0.540-3.730; p = 0.835). Propensity score-matching analysis between the recompensated and compensated groups (84 pairs) and propensity score-matching analysis between the recompensated and decompensated groups (62 pairs) showed similar results. CONCLUSIONS: Achieving recompensation reduced the risk of HCC in patients with HBV-related decompensated cirrhosis, while the risk remained comparable to that of compensated cirrhosis.