Revisiting calculation of tilt angles for double-tilt sample holders in transmission electron microscopes.

We revisited the formula related to the overall tilt angle of a specimen using a side-entry double-tilt sample holder in a transmission electron microscope. Initially, we examined existing formulas in the literature for calculating the overall tilt angle. Subsequently, a new formula was derived, proven to better account for the actions of the double-tilt holder, thereby providing improved accuracy in the calculation. This newly derived formula has been implemented in the Landyne software suite. Furthermore, we demonstrated the accuracy of the new formula through examples. RESEARCH HIGHLIGHTS: A new formula has been derived to calculate overall tilt angles for side-entry double-tilt holders in TEM.

Hybrid Cellular Nanovesicles Block PD-L1 Signal and Repolarize M2 Macrophages for Cancer Immunotherapy.

The PD1/PD-L1 immune checkpoint blocking is a promising therapy, while immunosuppressive tumor microenvironment (TME) and poor tumor penetration of therapeutic antibodies limit its efficacy. Repolarization of tumor-associated macrophages (TAMs) offers a potential method to ameliorate immunosuppression of TME and further boost T cell antitumor immunity. Herein, hybrid cell membrane biomimetic nanovesicles (hNVs) are developed by fusing M1 macrophage-derived nanovesicles (M1-NVs) and PD1-overexpressed tumor cell-derived nanovesicles (PD1-NVs) to improve cancer immunotherapy. The M1-NVs promote the transformation of M2-like TAMs to M1-like phenotype and further increase the release of pro-inflammatory cytokines, resulting in improved immunosuppressive TME. Concurrently, the PD1-NVs block PD1/PD-L1 pathway, which boosts cancer immunotherapy when combined with M1-NVs. In a breast cancer mouse model, the hNVs efficiently accumulate at the tumor site after intravenous injection and significantly inhibit the tumor growth. Mechanically, the M1 macrophages and CD8+ T lymphocytes in TME increase by twofold after the treatment, indicating effective immune activation. These results suggest the hNVs as a promising strategy to integrate TME improvement with PD1/PD-L1 blockade for cancer immunotherapy.

Zirconium and hafnium catalyzed C-C single bond hydroboration.

Selective cleavage and subsequent functionalization of C-C single bonds present a fundamental challenge in synthetic organic chemistry. Traditionally, the activation of C-C single bonds has been achieved using stoichiometric transition-metal complexes. Recently, examples of catalytic processes were developed in which use is made of precious metals. However, the use of inexpensive and Earth-abundant group IV metals for catalytic C-C single-bond cleavage is largely underdeveloped. Herein, the zirconium-catalyzed C-C single-bond cleavage and subsequent hydroboration reactions is realized using Cp2ZrCl2 as a catalytic system. A series of structures of various γ-boronated amines are readily obtained, which are otherwise difficult to obtain. Mechanistic studies disclose the formation of a N-ZrIV species, and then a ß-carbon elimination route is responsible for C-C single bond activation. Besides zirconium, hafnium exhibits a similar performance for this transformation.

Genetically Engineered Cytomembrane Nanovaccines for Cancer Immunotherapy.

Cancer nanovaccines have attracted widespread attention by inducing potent cytotoxic T cell responses to improve immune checkpoint blockade (ICB) therapy, while the lack of co-stimulatory molecules limits their clinical applications. Here, a genetically engineered cancer cytomembrane nanovaccine is reported that simultaneously overexpresses co-stimulatory molecule CD40L and immune checkpoint inhibitor PD1 to elicit robust antitumor immunity for cancer immunotherapy. The CD40L and tumor antigens inherited from cancer cytomembranes effectively stimulate dendritic cell (DC)-mediated immune activation of cytotoxic T cells, while the PD1 on cancer cytomembranes significantly blocks PD1/PD-L1 signaling pathway, synergistically stimulating antitumor immune responses. Benefiting from the targeting ability of cancer cytomembranes, this nanovaccines formula shows an enhanced lymph node trafficking and retention. Compared with original cancer cytomembranes, this genetically engineered nanovaccine induces twofold DC maturation and shows satisfactory precaution efficacy in a breast tumor mouse model. This genetically engineered cytomembrane nanovaccine offers a simple, safe, and robust strategy by incorporating cytomembrane components and co-stimulatory molecules for enhanced cancer immunotherapy.

The Impact of Surgical Approach on 90-Day Prosthetic Joint Infection After Total Hip Replacement - A Population-Based, Propensity Score-Matched Cohort Study.

BACKGROUND: Prosthetic joint infection (PJI) is a devastating complication of total hip arthroplasty (THA). This study aimed to determine if the anterior approach (AP) influenced the incidence of early PJI in THA compared to posterior approach (PP). METHODS: Record linkage was performed between state-wide hospitalization data and a national joint replacement registry to identify unilateral THA performed via the AP or PP. Complete data on 12,605 AP and 25,569 PP THAs were obtained. Propensity score matching (PSM) was undertaken to match covariates between the approaches. Outcomes were the 90-day PJI hospital readmission rate(using narrow and broad definitions) and 90-day PJI revision rate (defined as component removal or exchange). RESULTS: The raw PJI readmission rate for AP was lower than PP (0.8% versus 1.1%, respectively). In the PSM analysis, there was no statistically significant difference in PJI readmission rate between approaches using narrow or broad definition of PJI readmission. In terms of revision for infection, both methods showed AP had a significantly lower rate than PP, with an adjusted odds ratio (OR) of 0.47 (95% confidence interval (CI) 0.30, 0.75) for the 1:1 nearest neighbor method and 0.50 (95% CI 0.32, 0.77) for the subclassification method. CONCLUSION: After addressing known confounders, there was no significant difference in the 90-day hospital readmission rate for hip PJI between approaches. There was a significantly reduced 90-day PJI revision rate for AP. The difference in revision may reflect differences in the surgical management of PJI between hip approaches rather than a difference in the underlying rate of infection.

Effect and Mechanism of Curdione Combined with Gemcitabine on Migration and Invasion of Bladder Cancer.

Bladder cancer (BCa), which usually occurs in bladder epithelial cells and is the fifth most common type of cancer in the world. he recurrence rate within 5 years after surgery is 0.8-45% of patients with early bladder cancer. Therefore, finding appropriate drug therapy for patients with bladder cancer can provide a reference for clinical treatment and play an important role in improving the prognosis of patients. In this study, CCK8 assay result showed that the inhibition of bladder cancer cell activity by Curdione and GEM increased with time and dose. Subsequently, CCK8, clone formation assay and Transwell result showed Curdione enhances GEM inhibition of bladder cancer cell activity, clonal formation and migration, these combine therapeutic schedule also could inhibited growth of in vivo xenograft tumors. The comprehensive database showed that CA2 is a potential target genes of Curdione, and Knockdown CA2 enhances GEM induced inhibition of cell proliferation and migration. Based on these advantages, Curdione may be a new type of action drug or adjunct for the treatment of bladder cancer.

Effect of glutamine on the systemic innate immune response in broiler chickens challenged with Salmonella pullorum.

BACKGROUND: The objective of this study was to evaluate the effects of glutamine on the growth performance and systemic innate immune response in broiler chickens challenged with Salmonella pullorum. A total of 600 one-day-old Arbor Acres broiler chickens were assigned randomly to 6 dietary treatments with 10 replicates for a 21-day feeding experiment. The experimental treatments were as follows: the control treatment (birds fed the basal diet), the Gln1 treatment, and the Gln 2 treatment (birds fed the basal diet supplemented with 0.5%, and 1.0% Glutamine, respectively). At 3 d of age, half of the birds from each treatment were challenged oral gavage with 2.0 × 104 CFU/mL of S. pullorum suspension (1.0 mL per bird) or an equivalent amount of sterile saline alone, which served as a control. RESULTS: The results showed that S. pullorum infection had adverse effects on the average daily feed intake, average daily gain, and feed conversion ratio of broiler chickens compared with those of the CON treatment on d 7, decreased the spleen and bursa of fabricius relative weights (except on d 21), serum immunoglobulin A (IgA),immunoglobulin G (IgG), and immunoglobulin M (IgM) concentrations, and spleen melanoma differentiation-associated gene 5 (MDA5) and laboratory of genetics and physiology gene 2 (LGP2) mRNA expression levels, and increased the mRNA expression levels of spleen Nodinitib-1 (NOD1), Toll-like receptors 2,4 (TLR2, TLR4), DNA-dependent activator of IFN-regulatory factors (DAI), mitochondrial antiviral-signaling protein (MAVS), P50, P65, and RelB on d 4, 7, 14, and 21. Supplementation with Gln improved the relative weights of the spleen and bursa of Fabricius (except on d 21), increased the serum IgA, IgG, and IgM concentrations and the mRNA expression levels of spleen MDA5 and LGP2, and decreased the mRNA expression levels of spleen NOD1, TLR2, TLR4, DAI, MAVS, P50, P65, and RelB of S. pullorum-challenged broiler chickens. CONCLUSION: These results indicate that Gln might stimulate the systemic innate immune responses of the spleen in broiler chickens challenged with S. pullorum.

Identification of new bisabosqual-type meroterpenoids reveals non-enzymatic conversion of bisabosquals into seco-bisabosquals.

Bisabosqual-type meroterpenoids are fungi-derived polyketide-terpenoid hybrids bearing a 2,3,3a,3a1,9,9a-hexahydro-1H-benzofuro[4,3,2-cde]chromene skeleton (6/6/6/5 ring system) or its seco-C-ring structure, and exhibit diverse bioactivities. Their unique structural architecture and impressive biological activities have led to considerable interest in discovering new analogues. However, to date, only nine analogues have been identified. Herein, we reported the isolation and identification of six new bisabosqual-type meroterpenoids stachybisbins C-H (1-6), together with one known compound bisabosqual C (7), from Stachybotrys bisbyi PYH05-7. Intriguingly, we found that 7, which contains the intact tetracyclic skeleton, can be non-enzymatically converted into its seco derivative stachybisbin I (8), unveiling the biosynthetic relationship between bisabosquals and seco-bisabosquals. Moreover, based on CRISPR/Cas9-mediated gene disruption, we revealed that the three-gene cluster responsible for the formation of LL-Z1272ß is associated with the biosynthesis of bisabosqual-type meroterpenoids, and then proposed a plausible route to 1-8.

Nickel-Catalyzed Reductive [4 + 1] Sila-Cycloaddition of 1,3-Dienes with Dichlorosilanes.

Transition-metal-catalyzed sila-cycloaddition has been a promising tool for accessing silacarbocycle derivatives, but the approach has been limited to a selection of well-defined sila-synthons. Herein, we demonstrate the potential of chlorosilanes, which are industrial feedstock chemicals, for this type of reaction under reductive nickel catalysis. This work extends the scope of reductive coupling from carbocycle to silacarbocycle synthesis and from single C-Si bond formation to sila-cycloaddition reactions. The reaction proceeds under mild conditions and shows good substrate scope and functionality tolerance, and it offers new access to silacyclopent-3-enes and spiro silacarbocycles. The optical properties of several spiro dithienosiloles as well as structural variations of the products are demonstrated.

Vesicular Antibodies: Shedding Light on Antibody Therapeutics with Cell Membrane Nanotechnology.

The high stability of antibodies and their ability to precisely bind to antigens and endogenous immune receptors, as well as their susceptibility to protein engineering, enable antibody-based therapeutics to be widely applied in cancer, inflammation, infection, and other disorders. Nevertheless, the application of traditional antibody-based therapeutics has certain limitations, such as high price, limited permeability, and protein engineering complexity. Recent breakthroughs in cell membrane nanotechnology have deepened the understanding of the critical role of membrane protein receptors in disease treatment, enabling vesicular-antibody-based therapeutics. Here, the concept of vesicular antibodies that are obtained by modifying target antibodies onto cell membranes for biomedical applications is proposed. Given that an antibody is basically a protein, as an extension of this concept, vesicles or membrane-coated nanoparticles that use surface antibodies and protein receptors on cell membranes for biomedical applications as vesicular antibodies are defined. Furthermore, several engineering strategies for vesicular antibodies are summarized and how vesicular antibodies can be used in a variety of situations is highlighted. In addition, current challenges and future prospects of vesicular antibodies are also discussed. It is anticipated this perspective will provide new insights on the development of next-generation antibodies for enhanced therapeutics.

LncRNA BC promotes lung adenocarcinoma progression by modulating IMPAD1 alternative splicing.

BACKGROUND: The therapeutic value of targeted therapies in patients with lung cancer is reduced when tumours acquire secondary resistance after an initial period of successful treatment. However, the molecular events behind the resistance to targeted therapies in lung cancer remain largely unknown. AIMS: To discover the important role and mechanism of lncRNA BC in promoting tumor metastasis and influencing clinical prognosis of LUAD. MATERIALS & METHODS: Microarrays were used to screen a comprehensive set of lncRNAs with differential expression profiles in lung cancer cells. The functional role and mechanism of lncRNA were further investigated by gain- and loss-of-function assays. RNA pull-down, protein assays, and mass spectrometry were used to identify proteins that interacted with lncRNA. TaqMan PCR was used to measure lncRNA in lung adenocarcinoma and adjacent nontumor tissues from 428 patients. The clinical significance of lncRNA identified was statistically confirmed in this cohort of patients. RESULTS: In this study, we show that the long non-coding RNA BC009639 (BC) is involved in acquired resistance to EGFR-targeted therapies. Among the 235 long non-coding RNAs that were differentially expressed in lung cancer cell lines, with different metastatic potentials, BC promoted growth, invasion, metastasis, and resistance to EGFR-tyrosine kinase inhibitors (EGFR-TKIs), both in vitro and in vivo. BC was highly expressed in 428 patients with lung adenocarcinoma (LUAD) and high BC expression correlated with reduced efficacy of EGFR-TKI therapy. To uncover the molecular mechanism of BC-mediated EGFR-TKI resistance in lung cancer, we screened and identified nucleolin and hnRNPK that interact with BC. BC formed the splicing complex with nucleolin and hnRNPK to facilitate the production of a non-protein-coding inositol monophosphatase domain containing 1 (IMPAD1) splice variant, instead of the protein-coding variant. The BC-mediated alternative splicing (AS) of IMPAD1 resulted in the induction of the epithelial-mesenchymal transition and resistance to EGFR-TKI in lung cancer. High BC expression correlated with clinical progress and poor survival among 402 patients with LUAD. DISSCUSSION: Through alternative splicing, BC boosted the non-coding IMPAD1-203 transcript variant while suppressing the IMPAD1-201 variant. In order to control the processing of pre-mRNA, BC not only attracted RNA binding proteins (NCL, IGF2BP1) or splicing factors (hnRNPK), but also controlled the formation of the splicing-regulator complex by creating RNA-RNA-duplexes. CONCLUSION: Our results reveal an important role for BC in mediating resistance to EGFR-targeted therapy in LUAD through IMPAD1 AS and in implication for the targeted therapy resistance.

Nickel-Catalyzed Reductive Coupling of Chlorosilanes.

Organosilanes play essential roles in many important research areas. The use of readily available chlorosilanes to catalytically access these compounds is synthetically appealing but remains a long-standing challenge. Nickel-catalyzed reductive cross-coupling reaction has recently emerged as a promising protocol to arrive at this goal. This strategy allows the chlorosilanes to be coupled with various carbon electrophiles under mild conditions. These reactions afford organosilanes with improved molecular diversity, structural complexity, and functional group compatibility. This Concept article summarizes the recent advance on nickel-catalyzed reductive C-Si couplings of chlorosilanes.

Nickel-Catalyzed Cross-Electrophile 1,2-Silyl-Arylation of 1,3-Dienes with Chlorosilanes and Aryl Bromides.

Catalytic, three-component, cross-electrophile reactions have recently emerged as a promising tool for molecular diversification, but studies have focused mainly on the alkyl-carbonations of alkenes. Herein, the scope of this method has been extended to conjugated dienes and silicon chemistry through silylative difunctionalization of 1,3-dienes with chlorosilanes and aryl bromides. The reaction proceeds under mild conditions to afford 1,2-linear-silylated products, a selectivity that is different to those obtained from conventional methods via an intermediary of H(C)-η3 -π-allylmetal species. Preliminary mechanistic studies reveal that chlorosilane reacts with 1,3-diene first and then couples with aryl bromide.

Association Analysis between Genotype and Phenotype of α,β-Thalassaemia Carriers in Huizhou Area of Guangdong Province / 中国实验血液学杂志

OBJECTIVE@#To analyze the prevalence, genotype distribution and hematological characteristics of α,β-thalassaemia carriers in Huizhou area of Guangdong Province.@*METHODS@#10 809 carriers of simple β-thalassaemia and 1 757 carriers of α,β-thalassaemia were enrolled as our study cohort. The hematological parameters were detected by automated blood cell counters and automatic capillary electrophoresis. Suspension array technology, gap-polymerase chain reaction (gap-PCR) and PCR-reverse dot blot were used for the genotyping of thalassaemia carriers.@*RESULTS@#The prevalence of α,β-thalassaemia in Huizhou area of Guangdong Province was 1.99%. A total of 62 genotypes were detected, and the most prevalent genotype was --SEA/ αα, βCD41-42/ βN (19.29%), the next was --SEA/ αα, βIVS-II-654/ βN (16.73%). Significant differences in mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) were found between different genotype groups for simple β-thalassaemia and α,β-thalassaemia. Violin plots showed that carriers with co-inheritance of β-thalassaemia and mild α-thalassaemia expressed the lightest anemia, and carriers with co-inheritance of β-thalassaemia and hemoglobin H (Hb H) disease expressed the most severe anemia.@*CONCLUSION@#There is a high prevalence of α,β-thalassaemia in Huizhou area of Guangdong Province. Because of the lack of specific hematological makers for diagnosis of α,β-thalassaemia, it is necessary to distinguish it from simple β-thalassaemia by genotyping of α- and β-thalassaemia in order to correctly guide genetic counseling and prenatal disgnosis.

Canonical WNT Signaling Activated by WNT7B Contributes to L-HBs-Mediated Sorafenib Resistance in Hepatocellular Carcinoma by Inhibiting Mitophagy.

Hepatocellular carcinoma (HCC) is the third leading cause of cancer death globally, with hepatitis B virus (HBV) infection accounting for over half of all cases. HBV leads to the development of HCC according to a body of literature. Our previous research and other studies also suggest that HBV causes chemotherapeutic treatment resistance, however, the mechanism is uncertain. The WNT family, which encodes secreted signaling molecules, has been linked to carcinogenesis in a variety of malignancies, including HCC. However, little is known regarding WNT7B, a WNT ligand, in the development of HCC and HBV-induced chemoresistance. In this study, the bioinformatics analysis and immunohistochemistry (IHC) staining of clinical samples revealed that WNT7B was overexpressed in HBV-associated HCC tissues versus nontumor liver tissues, which was related to HCC patient survival. Further study in vitro showed that WNT7B and its receptor frizzled-4 (FZD4) were upregulated in response to large hepatitis B surface antigens (L-HBs). L-HBs increased canonical WNT signaling in HCC cells through WNT7B/FZD4. According to functional experiments, WNT7B enhanced the cell proliferation and metastasis in HCC. In vivo and in vitro studies investigated whether L-HBs induced sorafenib resistance by WNT7B in HCC. Interestingly, L-HBs suppressed sorafenib-induced mitophagy by increasing WNT7B/CTNNB1 signaling, resulting in chemoresistance. The findings revealed that WNT7B could be a promising molecular therapeutic target as well as a predictor of sorafenib resistance in HBV-related HCC. The suppression of HBV structural proteins such as L-HBs may play a crucial role in systemic chemotherapy resistance in HBV-associated HCC.

Noninvasive prenatal diagnosis targeting fetal nucleated red blood cells.

Noninvasive prenatal diagnosis (NIPD) aims to detect fetal-related genetic disorders before birth by detecting markers in the peripheral blood of pregnant women, holding the potential in reducing the risk of fetal birth defects. Fetal-nucleated red blood cells (fNRBCs) can be used as biomarkers for NIPD, given their remarkable nature of carrying the entire genetic information of the fetus. Here, we review recent advances in NIPD technologies based on the isolation and analysis of fNRBCs. Conventional cell separation methods rely primarily on physical properties and surface antigens of fNRBCs, such as density gradient centrifugation, fluorescence-activated cell sorting, and magnetic-activated cell sorting. Due to the limitations of sensitivity and purity in Conventional methods, separation techniques based on micro-/nanomaterials have been developed as novel methods for isolating and enriching fNRBCs. We also discuss emerging methods based on microfluidic chips and nanostructured substrates for static and dynamic isolation of fNRBCs. Additionally, we introduce the identification techniques of fNRBCs and address the potential clinical diagnostic values of fNRBCs. Finally, we highlight the challenges and the future directions of fNRBCs as treatment guidelines in NIPD.

Preparation of antioxidant peptides from Moringa oleifera leaves and their protection against oxidative damage in HepG2 cells.

Moringa oleifera leaves are a kind of new food raw materials, rich in functional factors, M. oleifera leaves aqueous extract have antioxidant activity and M. oleifera leave protein is an important active ingredient in the aqueous extract. Numerous studies have shown that peptides have strong antioxidant activity. To reveal the antioxidant effects of M. oleifera (MO) leaves peptides, MO leave antioxidant peptides were isolated and prepared to clarify their antioxidant activity. MLPH1 (<1 kDa), MLPH3 (1~3 kDa), MLPH5 (3~5 kDa), and MLPH10 (5~10 kDa) fractions were obtained by the membrane ultrafiltration classification of MO leaves proteolytic hydrolysate (MLPH). MLPH1 was further separated by centrifugal filters, and the fraction separated by <1 kDa (MLPH1-1) was identified and analyzed by LC-MS/MS. The purpose of this study was to investigate the effect of MO leaves antioxidant peptide pretreatment on H2O2-treated HepG2 cells and to refine the antioxidant activity. The results showed that MLPH1 had the strongest antioxidant activity, and three MO leaves antioxidant peptides (LALPVYN, LHIAALVFQ, and FHEEDDAKLF) were obtained. The peptide with the sequence LALPVYN and a molecular weight of 788.44 Da had the strongest antioxidant activity. After 24 h of LALPVYN pretreatment, the cell viability and the CAT, GSH-Px, and SOD enzyme activity were significantly increased, and the MDA, ROS, and apoptosis rates were significantly decreased. These results provide a theoretical basis for further research on the antioxidant mechanism of MO leaves peptides.