Revisiting Pentazole: An Investigation into the Intriguing Molecule Exhibiting Dual Organic and Inorganic Characteristics.

Pentazole (cyclo-HN5) is a unique heterocycle categorized as both an organic and inorganic compound. However, attempts to synthesize and characterize cyclo-HN5 have been unsuccessful thus far. In this study, we synthesized a cyclo-HN5 solution and investigated the spectra, structure, aromaticity, acidity, and stability of cyclo-HN5. The lone pair of electrons on the protonated N atom of cyclo-HN5 participates in π-electron delocalization, forming two N═N bonds. Further investigations suggest that cyclo-HN5 exhibits significantly decreased π aromaticity and slightly lower σ aromaticity than cyclo-N5-. Experimental results suggest that pure cyclo-HN5 is unstable at ambient temperatures and pressures, but it can be isolated at high pressures or stabilized in solution by abundant hydrogen bonds. The pKa of cyclo-HN5 was determined as 1.63 (H2O, 25 °C) via potentiometric titration, indicating that cyclo-HN5 is a medium-strong acid. This study reveals the fundamental structure and properties of cyclo-HN5, thereby providing important data for advancing cyclo-HN5 chemistry.

Non-Fully Conjugated Dimerized Giant Acceptors with Different Alkyl-Linked Sites for Stable and 19.13 % Efficiency Organic Solar Cells.

Achieving both high power conversion efficiency (PCE) and device stability is a major challenge for the practical development of organic solar cells (OSCs). Herein, three non-fully conjugated dimerized giant acceptors (named 2Y-sites, including wing-site-linked 2Y-wing, core-site-linked 2Y-core, and end-site-linked 2Y-end) are developed. They share the similar monomer precursors but have different alkyl-linked sites, offering the fine-tuned molecular absorption, packing, glass transition temperature, and carrier mobility. Among their binary active layers, D18/2Y-wing has better miscibility, leading to optimized morphology and more efficient charge transfer compared to D18/2Y-core and D18/2Y-end. Therefore, the D18/2Y-wing-based OSCs achieve a superior PCE of 17.73 %, attributed to enhanced photocurrent and fill factor. Furthermore, the D18/2Y-wing-based OSCs exhibit a balance of high PCE and improved stability, distinguishing them within the 2Y-sites. Building on the success of 2Y-wing in binary systems, we extend its application to ternary OSCs by pairing it with the near-infrared absorbing D18/BS3TSe-4F host. Thanks to the complementary absorption within 300-970 nm and further optimized morphology, ternary OSCs obtain a higher PCE of 19.13 %, setting a new efficiency benchmark for the dimer-derived OSCs. This approach of alkyl-linked site engineering for constructing dimerized giant acceptors presents a promising pathway to improve both PCE and stability of OSCs.

Nanoporous Graphene Oxide-Based Quartz Crystal Microbalance Gas Sensor with Dual-Signal Responses for Trimethylamine Detection.

This paper presents a straightforward method to develop a nanoporous graphene oxide (NGO)-functionalized quartz crystal microbalance (QCM) gas sensor for the detection of trimethylamine (TMA), aiming to form a reliable monitoring mechanism strategy for low-concentration TMA that can still cause serious odor nuisance. The synthesized NGO material was characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy to verify its structure and morphology. Compared with the bare and GO-based QCM sensors, the NGO-based QCM sensor exhibited ultra-high sensitivity (65.23 Hz/µL), excellent linearity (R2 = 0.98), high response/recovery capability (3 s/20 s) and excellent repeatability (RSD = 0.02, n = 3) toward TMA with frequency shift and resistance. Furthermore, the selectivity of the proposed NGO-based sensor to TMA was verified by analysis of the dual-signal responses. It is also proved that increasing the conductivity did not improve the resistance signal. This work confirms that the proposed NGO-based sensor with dual signals provides a new avenue for TMA sensing, and the sensor is expected to become a potential candidate for gas detection.

Pressure Effects on Structure and Optical Properties in Cesium Lead Bromide Perovskite Nanocrystals.

Metal halide perovskites (MHPs) are gaining increasing interest because of their extraordinary performance in optoelectronic devices and solar cells. However, developing an effective strategy for achieving the band-gap engineering of MHPs that will satisfy the practical applications remains a great challenge. In this study, high pressure is introduced to tailor the optical and structural properties of MHP-based cesium lead bromide nanocrystals (CsPbBr3 NCs), which exhibit excellent thermodynamic stability. Both the pressure-dependent steady-state photoluminescence and absorption spectra experience a stark discontinuity at ∼1.2 GPa, where an isostructural phase transformation regarding the Pbnm space group occurs. The physical origin points to the repulsive force impact due to the overlap between the valence electron charge clouds of neighboring layers. Simultaneous band-gap narrowing and carrier-lifetime prolongation of CsPbBr3 trihalide perovskite NCs were also achieved as expected, which facilitates the broader solar spectrum absorption for photovoltaic applications. Note that the values of the phase change interval and band-gap red-shift of CsPbBr3 nanowires are between those for CsPbBr3 nanocubes and the corresponding bulk counterparts, which results from the unique geometrical morphology effect. First-principles calculations unravel that the band-gap engineering is governed by orbital interactions within the inorganic Pb-Br frame through structural modification. Changes of band structures are attributed to the synergistic effect of pressure-induced modulations of the Br-Pb bond length and Pb-Br-Pb bond angle for the PbBr6 octahedral framework. Furthermore, the significant distortion of the lead-bromide octahedron to accommodate the Jahn-Teller effect at much higher pressure would eventually lead to a direct to indirect band-gap electronic transition. This study enables high pressure as a robust tool to control the structure and band gap of CsPbBr3 NCs, thus providing insight into the microscopic physiochemical mechanism of these compressed MHP nanosystems.

Screening of broad-spectrum aptamer and development of electrochemical aptasensor for simultaneous detection of penicillin antibiotics in milk.

Penicillin antibiotics (PENs) play an important role in killing pathogenic bacteria. However, the residues of various penicillin antibiotics in milk gradually accumulate in the human body with the increase of milk intake, which causes direct harm to the human body. Aptamers can be used as recognition element of sensors. It is great significance to use broad-spectrum aptamers for simultaneous detection of PENs. In this study, we reported the screening and identification of DNA aptamers for PENs. The aptamers were screened by graphene oxide-systematic evolution of ligands by exponential enrichment (GO-SELEX). The broad-spectrum aptamers with high affinity and specificity were successfully obtained after 13 rounds of screening. The affinity and specificity of candidate aptamers were analyzed by a GO fluorescence competition method. Further sequence analysis revealed that a truncated 47 nt aptamer (P-11-1) had a higher affinity than the original 79 nt aptamer. The truncated aptamer P-11-1 was used as a recognition element, and an electrochemical aptasensor was prepared using gold nanoparticles (AuNPs) combined with ferroferric oxide-multi walled carbon nanotube (Fe3O4-MWCNTs) complex. The results showed that the developed aptasensor achieved the simultaneous detection of PENs in milk samples across a concentration range of 2 nM-10,000 nM, achieving a limit of detection of 0.667 nM. This methodology provided a simple and sensitive new thinking for antibiotic multi-residue detection.

Association between fine particulate matter and heart failure hospitalizations: a time-series analysis in Yancheng, China.

BACKGROUND: Heart failure (HF) is a global public health problem of increasing importance. The association between acute exposure to air pollution and HF has been well established in developed countries, but little evidence is available in developing countries where air pollution levels are much higher. OBJECTIVES: To explore the associations between PM2.5 and HF hospitalizations in Yancheng, China. METHODS: In this time-series study, daily HF hospitalizations admitted in three major hospitals in Yancheng from May 1, 2015 to Apr 30, 2020 were collected. We used a generalized additive model with quasi-Poisson regression to investigate the association between PM2.5 and HF hospitalizations. The robustness of the associations was tested using two-pollutant models, and we examined the potential effect modification by age, gender, and season via stratification analyses. Lastly, we pooled the concentration-response curves. RESULTS: A total of 10,466 HF hospitalizations were recorded, with a daily average of 6 cases. We observed the most robust estimates on lag 0 day, and the associated increment in HF was 1.28% (95% CI 0.45%, 2.11%) for a 10-µg/m3 increase of PM2.5. The association remained after adjustment of O3, but not for NO2, CO, and SO2. The PM2.5-HF associations were positive in females, patients aged ≥ 65 years, and in cold season. The C-R relationship curve was generally increasing below 30 µg/m3. CONCLUSION: This study provided evidence on the association of PM2.5 with acute exacerbation of chronic heart failure, which may benefit future prevention strategy and policymaking.

Structural stability and optical properties of two-dimensional perovskite-like CsPb2Br5 microplates in response to pressure.

Here, we report the structural stability and visible light response of two-dimensional (2D) layered perovskite-like CsPb2Br5 microplates (MPs) under high pressure. In situ high-pressure emission, optical absorption, and angle dispersive synchrotron X-ray diffraction indicated that CsPb2Br5 MPs experienced an isostructural phase transformation at roughly 1.6 GPa. The shrinkage of Pb-Br bond lengths and the marked change of Br-Pb-Br bond angles within the lead-bromide pentahedral motif were responsible for the pressure-induced structural modulation and the sudden band-gap change of CsPb2Br5 MPs.

[The relationship between endothelin receptors and chronic venous insufficiency of lower extremities].

OBJECTIVE: To investigate the effect of endothelin receptors in chronic venous insufficiency (CVI) in lower extremities. METHODS: Ten cases of varicose veins from CVI patients (as case group) and ten cases of non-varicose veins (as control group) were investigated in this study. The two groups were divided into two groups respectively: endothelium-intact group and de-endothelium groups. The vasoconstriction mediated by endothelin A (ETA) and endothelin B (ETB) receptors was recorded with myography. The distribution of ETA and ETB receptors was detected by immunohistochemistry method. RESULTS: Endothelin-1 (ET-1) and sarafotoxin 6c (S6c) induced concentration-dependent contraction in the veins. In endothelium-intact veins, the E(max) and pD(2) of contraction curve induced by ET-1 were 132.30% +/- 43.42% and 6.03 +/- 0.35, respectively in control group;and were 19.24% +/- 12.94% and 6.78 +/- 0.46, respectively in case group. The E(max) and pD(2) in case group were much lower than in control group (P < 0.05). The E(max) and pD(2) induced by S6c were 30.10% +/- 12.90% and 6.54 +/- 0.36, respectively in control group, and were 9.61% +/- 1.32% and 6.75 +/- 0.29, respectively in case group; The E(max) in case group was lower than in control group (P < 0.05). In de-endothelium veins, E(max) and pD(2) of S6c were 146.18% +/- 32.33% and 6.50 +/- 0.17 in control group, and 32.93% +/- 3.00% and 6.69 +/- 0.39 in case group; The E(max) in case group was significantly lower than in control group (P < 0.05). ETA receptors was located in endothelium mainly, and ETB receptors in smooth muscle cells mainly. The sites of both ETA and ETB receptors were decreased in case group obviously. CONCLUSIONS: The contraction mediated by ETA receptor and ETB receptor was decreased with a decrease of ETA receptor and ETB receptor sites in varicose veins of CVI. The contraction insufficiency and down-expression of ETA receptor and ETB receptor are correlated with CVI.

Bornyl acetate suppresses ox-LDL-induced attachment of THP-1 monocytes to endothelial cells.

Leukocyte recruitment to the surface of the endothelium plays a pivotal role in the development of cardiovascular diseases. Bornyl acetate is the main volatile constituent present in numerous conifer oils, which has displayed its anti-oxidant and anti-inflammatory properties in different types of tissues and cells. However, little information regarding the effects of bornyl acetate on vascular endothelial inflammation has been reported before. In the current study, we aimed to investigate the pharmacological roles of bornyl acetate against ox-LDL-induced leukocyte adhesion to the endothelium. Our findings indicate that bornyl acetate ameliorated ox-LDL-induced reduction in cell viability of HUVECs. Additionally, bornyl acetate inhibited the attachment of THP-1 monocytes to HUVECs induced by treatment with ox-LDL through ameliorating the expression of ICAM-1, VCAM-1, and E-selectin. Mechanistically, we found that bornyl acetate could suppress activation of the IκBα/NF-κB signaling pathway. Lastly, our results indicate that bornyl acetate mitigated expression of the pro-inflammatory cytokines TNF-α and IL-1ß. Our results suggest the therapeutic potential of bornyl acetate in patients with atherosclerosis.

The middle-term outcome of carotid endarterectomy and stenting for treatment of ischemic stroke in Chinese patients.

This study aims to investigate the complication and middle-term outcome of carotid endarterectomy (CEA) and carotid artery stenting (CAS) in Chinese patients, which was a retrospective case-control study and perioperative complications and 2-year end points were analyzed. Follow-up was done by a certified doctor, and restenosis was detected by ultrasound. Operation success rate were 100% in two groups. CAS showed the higher incidence rate of all stroke/TIA at 30days post-procedure (7.89% VS 1.85%, P = 0.038), odds ratio (OR) with 95% confidence interval, 4.54 (1.09-18.97), but there was no difference in the incidence rate of stroke subgroups, mortality and myocardial infarction between two groups. The higher incidence of hypertension with CEA (14.42% VS 5.26%, P = 0.012), OR: 2.90 (1.26-6.65) and hypotension with CAS (14.91% VS 1.85%, P = 0.001), OR: 0.11 (0.03-0.42). No difference in all stroke, ipsilateral stroke and mortality between two groups at 24 months post-procedures, however, the total incidence rate of stroke/death was higher in CAS (12.84% VS 4.72%, P = 0.036), OR: 2.98 (1.08,8.23). Higher restenosis rate of CAS was examined (13.76% VS 5.66%, P = 0.045), OR: 2.66 (1.02, 6.74). CAS and CEA showed a similar middle-term outcome, but CAS showed a higher incidence rate of stroke and restenosis after operation.

Mechanism of the effect of saikosaponin on atherosclerosis in vitro is based on the MAPK signaling pathway.

The present study aimed to investigate the effects of saikosaponin on oxidized low­density lipoprotein (ox­LDL)­induced human umbilical vein endothelial cell (HUVEC) injury and apoptosis, and examine the involvement of the mitogen­activated protein kinase (MAPK) signaling pathway. The viability and apoptosis of HUVECs were detected using an MTT assay and flow cytometry. ELISA analysis was applied to measure the levels of tumor necrosis factor (TNF)­α and interleukin (IL)­6 cytokines. Nuclear factor (NF)­κB p65 nuclear translocation was observed using immunofluorescence staining. The levels of intercellular adhesion molecule 1 and vascular cell adhesion molecule­1 were detected using reverse transcription­polymerase chain reaction analysis. The phosphorylation of B­cell lymphoma 2 (Bcl­2), Bcl­2­associated X protein (Bax), caspase­3 p38, c­Jun N­terminal kinase (JNK) and extracellular signal­regulated kinase (ERK)1/2 were detected using western blot analysis. The results revealed that saikosaponin increased the viability of the HUVECs and decreased the early­stage apoptotic rate of the HUVECs induced by ox­LDL. The expression levels of inflammatory cytokines in the injured vascular endothelial cells were decreased, the expression levels of adhesion molecules were reduced, the activity of superoxide dismutase was increased, and malondialdehyde content was decreased. Therefore, the inflammatory response and oxidative stress were inhibited. Simultaneously, the levels of Bcl­2 increased, the levels of Bax and caspase­3 decreased, and the nuclear translocation of NF­κB p65 was significantly inhibited. The protein levels of phosphorylated p38 and JNK were reduced, whereas that of ERK1/2 remained unaffected. It was concluded that the MAPK signaling pathway mediated HUVEC injury induced by ox­LDL. However, saikosaponin inhibited the HUVEC injury induced by ox­LDL through inhibiting the ERK1/2 and p38 MAPK signaling pathways, and possibly also through the JNK and p38 MAPK signaling pathway.

Compressed few-layer black phosphorus nanosheets from semiconducting to metallic transition with the highest symmetry.

The high-pressure response of few-layer black phosphorus (BP) nanosheets remains elusive, despite the special interest in it particularly after the achievement of an exotic few-layer BP based field effect transistor. Here, we identified a pressure-induced reversible phase transition on few-layer BP nanosheets by performing in situ ADXRD and Raman spectroscopy with the assistance of DAC apparatus. The few-layer BP nanosheets transformed from orthorhombic semiconductors to simple cubic metal with increasing pressure, which is well interpreted using the pressure-induced inverse Peierls distortion. The obtained simple cubic BP nanosheets exhibited an enhanced isothermal bulk modulus of 147.0(2) GPa, and negative Grüneisen parameters that were attributed to the pressure-driven softening of phonon energies. Note that the simple cubic BP nanosheets adopted the highest symmetry which is in stark contrast to the general phase transformation under high pressure. First-principles calculations indicated that the metallic BP was significantly related to the band overlapped metallization, resulting from the traversing of density of states across the Fermi level at high pressure. Such findings paved a potential pathway to design targeted BP nanostructures with functional properties at extremes, and opened up possibilities for conceptually new devices.

Visible mechanochromic responses of spiropyrans in crystals via pressure-induced isomerization.

The isomerization of spiropyrans in crystals was realized under high pressure, and the corresponding mechanochromic response could be observed by the naked eye. In situ UV-Vis spectroscopy study demonstrated that the equilibrium constant increases with the increasing pressure, from which we proposed that the negative volume of reaction determined the isomerization under high pressure.

Development and validation of a lateral flow immunoassay using colloidal gold for the identification of serotype-specific foot-and-mouth disease virus O, A and Asia 1.

A lateral flow immunoassay (LFI) was developed to identify and diagnose foot-and-mouth disease virus (FMDV) serotypes O, A and Asia 1. Antibodies obtained from rabbits and guinea pigs immunized with cell-culture-adapted virus strains (O/CHA/99, A/GS/LX/66, Asia 1/CHN/05) and suckling-mouse adapted virus strains (O/AV99(L), A/AV88(L), Asia 1/YNBS/58) were used as capture antibodies. The diagnostic kit included three immunochromatographic strips of types O, A and Asia 1, and the type-specific results were confirmed by color on the test lines of the three strips. The LFI was evaluated using epithelial and vesicular samples (n=396) prepared from current and historical field samples (provide by the National Foot-and-Mouth Disease Reference Laboratory of China at Lanzhou Veterinary Research Institute). Negative samples (n=95) were collected from healthy animals. The diagnostic sensitivity of the LFI for FMDV serotypes O, A and Asia 1 was 88.3% compared to 89.7% obtained by the reference method of indirect-sandwich ELISA. The sensitivity of the LFI for FMDV type Asia 1 was higher at 92.1% compared to 90.5% for the ELISA. The specificity of the LFI was 97.1% compared with 97.4%.

A simple and rapid colloidal gold-based immunochromatogarpic strip test for detection of FMDV serotype A.

A sandwich format immunochromatographic assay for detecting foot-and-mouth disease virus (FMDV) serotypes was developed. In this rapid test, affinity purified polyclonal antibodies from Guinea pigs which were immunized with sucking-mouse adapted FMD virus (A/AV88(L) strain) were conjugated to colloidal gold beads and used as the capture antibody, and affinity purified polyclonal antibodies from rabbits which were immunized with cell-culture adapted FMD virus (A/CHA/09 strain) were used as detector antibody. On the nitrocellulose membrane of the immunochromatographic strip, the capture antibody was laid on a sample pad, the detector antibody was printed at the test line(T) and goat anti-guinea pigs IgG antibodies were immobilized to the control line(C). The lower detection limit of the test for a FMDV 146S antigen is 11.7 ng/ml as determined in serial tests after the strip device was assembled and the assay condition optimization. No cross reactions were found with FMDV serotype C, Swine vesicular disease (SVD), Vesicular stomatitis virus (VSV) and vesicular exanthema of swine virus (VES) viral antigens with this rapid test. Clinically, the diagnostic sensitivity of this test for FMDV serotypes A was 88.7% which is as same as an indirect-sandwich ELISA. The specificity of this strip test was 98.2% and is comparable to the 98.7% obtained with indirect-sandwich ELISA. This rapid strip test is simple, easy and fast for clinical testing on field sites; no special instruments and skills are required, and the result can be obtained within 15 min. To our knowledge, this is the first rapid immunochromatogarpic assay for serotype A of FMDV.