Construction of Hierarchical Porous UiO-66-Br2@PS/DVB-Packed Columns by High Internal Phase Emulsion Strategy for Enhanced Separation of CF4/N2 and SF6/N2.

Recovery and separation of anthropogenic emissions of electronic specialty gases (F-gases, such as CF4 and SF6) from the semiconductor sector are of critical importance. In this work, the hierarchical porous UiO-66-Br2@PS/DVB-packed column was constructed by a high internal phase emulsions strategy. UiO-66-Br2@PS/DVB exhibits a superior selectivity of CF4/N2 (2.67) and SF6/N2 (3.34) predicted by the IAST due to the diffusion limitation in the micropore and the gas-framework affinity. Especially, UiO-66-Br2@PS/DVB showed significant CF4 and SF6 retention and enabled the successful separation of CF4/N2 and SF6/N2 with a resolution of 2.37 and 8.89, respectively, when used as a packed column in gas chromatography. Compared with the Porapak Q column, the HETP of the UiO-66-Br2@PS/DVB-packed column decreased and showed good reproducibility. This research not only offers a convenient method for fabricating a hierarchical porous MOF-packed column but also showcases the prospective utilization of MOFs for the separation of the F-gas/N2 mixture.

Defective UiO-66-NH2 (Zr) for Simultaneous Adsorption of Phosphate and Pb2+ for Hydrogen Peroxide Purification.

Removal of hetero ions from the hydrogen peroxide solution is a crucial step in purifying electronic-grade H2O2. Conventional adsorption materials are challenged to meet the need for the simultaneous adsorption of both anions and cations in solvents. UiO-66 (Zr) modified by acetic acid and amino group for simultaneous adsorption of phosphate and Pb2+ in H2O2 purification was fabricated in this work. The as-prepared defective UiO-66-NH2 (Zr) demonstrated a significant increase in specific surface area and porosity, along with more exposed sites for phosphate and Pb2+ adsorption. The adsorption capacity of De-UiO-66-NH2 for phosphate and Pb2+ in H2O2 solution was 52.28 mg g-1 and 35.4 mg g-1, which is 1.19 times and 1.88 times that of unmodified UiO-66 (Zr), respectively. The trace simultaneous adsorption with both 100 ppb phosphate and Pb2+ showed removal rates of 94.0% and 88.7%, respectively, confirming the practicality of MOF materials in the purification of electronic chemicals. This work highlights the potential of Zr-based MOFs as anionic and cationic simultaneous adsorbents for highly efficient purification of electronic-grade solvents.

High-Temperature Liquid-Liquid Phase Transition in Glass-Forming Liquid Pd43Ni20Cu27P10.

Liquid-liquid phase transition (LLPT) is a transition from one liquid state to another with the same composition but distinct structural change, which provides an opportunity to explore the relationships between structural transformation and thermodynamic/kinetic anomalies. Herein the abnormal endothermic LLPT in Pd43Ni20Cu27P10 glass-forming liquid was verified and studied by flash differential scanning calorimetry (FDSC) and ab initio molecular dynamics (AIMD) simulations. The results show that the change of the atomic local structure of the atoms around the Cu-P bond leads to the change in the number of specific clusters <0 2 8 0> and <1 2 5 3>, which leads to the change in the liquid structure. Our findings reveal the structural mechanisms that induce unusual heat-trapping phenomena in liquids and advance the understanding of LLPT.

Enhancing undergraduate research talents: the role of tutors in dental basic research education.

Purpose: This study endeavors to investigate ways to optimize the role of teachers in undergraduate dental basic research education (UDBRE) with the aim of nurturing the research potential of undergraduate students. Methods: We conducted a cross-sectional study among medical undergraduates enrolled at the School of Stomatology, Guangzhou Medical University. Descriptive statistics were employed to comprehensively analyze UDBRE's fundamental aspects. Kendall rank correlation analysis was performed to evaluate the relationship between the quality of feedback provided by tutors to undergraduates and the students' scientific research abilities. Additionally, multivariate logistic regression analysis was employed to uncover the factors influencing the effectiveness of UDBRE. Results: A total of 168 medical students were surveyed with a valid response rate of 93.85%. The effectiveness of UDBRE was demonstrated by undergraduates' self-rated research abilities, active participation in scientific research projects, and a certain amount of academic outputs. Significant and positive correlations (𝓣b> 0.5, p < 0.001) were identified between the tutor-undergraduate feedback quality and students' self-rated scores for scientific research abilities. These abilities included developing scientific questions, designing research projects, retrieving and reading literature, academic writing, experiment operation, and analyzing and evaluating experimental results. Positive effects on students' academic performance (p < 0.05) were observed when higher-quality feedback, an authoritative tutoring style and tutors with middle-career experience were present. Conclusion: This study underscores the pivotal role of UDBRE in fostering the scientific research aptitude of medical undergraduates. It emphasizes the constructive influence of tutor-undergraduate feedback, authoritative teaching styles, providing valuable insights for establishing an effective mentorship framework.

Mental health status of medical students during postgraduate entrance examination.

BACKGROUND: The postgraduate entrance examination can be a milestone for many medical students to advance their careers. An increasing number of students are competing for limited postgraduate offers available, and failure to enter postgraduate studies can have adverse mental health consequences. In this paper, we aim to investigate the mental health status of medical students during the postgraduate application entrance examination and to provide a targeted basis for mental health education and psychological counselling. METHODS: Using the Symptom Checklist-90 scale (SCL-90) questionnaire, the mental health status of 613 students who passed two rounds of the Postgraduate Entrance Examination in 2019 to enroll in Guangzhou Medical University in China was evaluated and followed up for retesting 6 months later. We used SPSS 20.0 statistical software for comparative analysis, including One-Sample T-Test, Independent-Samples T-Test, Paired Samples T-Test and Chi-square Test. RESULTS: Our data showed that 12.10% of students had mental health problems during the postgraduate entrance examination, and it decreased significantly to 4.40% at the 6-month follow-up after the examination period finished (P < 0.01). Somatization was the most significant symptom of the students both during and after the postgraduate entrance examination stages. All SCL-90 factors were scored significantly lower both in and after the postgraduate entrance examination stages than the 2008 national college student norm score (P < 0.01). Excluding psychiatric factors, all other SCL-90 factors in the postgraduate entrance examination stage scored higher than the graduate stage (P < 0.05), and the total score of SCL-90 in female medical students was higher compared to male students (P < 0.05). CONCLUSION: The postgraduate entrance examination event has a significant negative influence on students' mental health. The mental health of college and graduate students as an important part of their higher education experience should be systematically studied, and psychological counselling or help should be provided to them throughout their studies, specifically during the examination period. Educating applicants about mental health should be implemented during the postgraduate entrance examination curriculum.

Synthesis of Diversified Pyrazolo[3,4-b]pyridine Frameworks from 5-Aminopyrazoles and Alkynyl Aldehydes via Switchable C≡C Bond Activation Approaches.

A cascade 6-endo-dig cyclization reaction was developed for the switchable synthesis of halogen and non-halogen-functionalized pyrazolo[3,4-b]pyridines from 5-aminopyrazoles and alkynyl aldehydes via C≡C bond activation with silver, iodine, or NBS. In addition to its wide substrate scope, the reaction showed good functional group tolerance as well as excellent regional selectivity. This new protocol manipulated three natural products, and the arylation, alkynylation, alkenylation, and selenization of iodine-functionalized products. These reactions demonstrated the potential applications of this new method.

Steric Hindrance Governs the Photoinduced Structural Planarization of Cycloparaphenylene Materials.

Cycloparaphenylenes ([n]CPPs) and their derivatives are known for the unique size-dependent photophysical properties, which are largely attributed to the structural planarization-associated exciton localization, attracting substantial research attention. In this work, we show that the steric hindrance between neighboring structural units plays a key role in governing the photoinduced global/local structural planarization and electron-hole distribution features of [n]CPP materials, due to the tunable strength of H···H repulsion between neighboring units via structural modification or C-H distance variation as revealed by density functional theory (DFT) and time-dependent DFT calculations. According to our results, steric hindrance controls the manner and also the extent of excited-state structural planarization, where a weak (strong) steric hindrance favors (hinders) structural planarization upon relaxation in the first excited singlet (S1) state as compared to the ground (S0)-state structure. Depending on the molecular structures, steric hindrance leads to fully delocalized, partially separated, or more localized electron-hole distributions. For example, via H···H repulsion release by manually shortening the C-H distance or by chemical substitution of C-H with N atoms, the modified [10]CPP structures show fully planarized configurations (each dihedral angle can be less than 2°) and entirely delocalized electron-hole distribution upon photorelaxation. This work provides insights into the structural origin of the unusual photophysical properties of [n]CPPs and shows the promise of steric hindrance tuning in accessing diverse excited-state features in [n]CPP materials.

Iodine-catalyzed oxidative annulation: facile synthesis of pyrazolooxepinopyrazolones via methyl azaarene sp3 C-H functionalization.

An iodine-catalyzed methyl azaarene sp3 C-H functionalization has been developed for the synthesis of a seven-membered O-heterocyclic architecture containing three different heterocyclic aromatic hydrocarbons. This method can be applied to a wide range of substituted methyl azaarenes and diverse 2,4-dihydro-3H-pyrazol-3-ones, and brings about the efficient preparation of 2,9-dihydrooxepino[2,3-c:6,5-c']dipyrazol-3(7H)-ones in high yields with the merits of low catalyst loading, good functional group tolerance and metal-free conditions.

Obg-Like ATPase 1 Enhances Chemoresistance of Breast Cancer via Activation of TGF-ß/Smad Axis Cascades.

Understanding the molecular mechanism of drug resistance helps to identify an effective target for breast cancer therapy. In this study we investigated the regulatory role of Obg-like ATPase 1 which is involved in multiple uses of drug resistance against breast cancer. Paclitaxel resistant cell line (MCF-7-PTR) was developed by a continuous increasing paclitaxel concentration. MTT assay was used to validate either acquired resistant or OLA1 modified cell lines. qRT-PCR, western blotting, apoptosis, and cell cycle assays were executed to evaluate gene and protein expression in cell lines. A series of in vitro assays was performed in the cells with RNAi-mediated knockdown to expound the regulatory function of OLA1 in breast cancer. We demonstrated that OLA1 was highly correlated with either acquired or intrinsic resistance of breast cancer. Further study showed that escalated expression of OLA1 promoted the EMT process in tumor cells through TGF-ß/Smad signaling cascades, resulting in the enhanced expression of anti-apoptosis-related proteins (cleaved caspase3, Bax, Bcl-2) and the strengthening depolymerization of microtubules in tumor cells. Our findings revealed that OLA1 enhanced the anti-apoptotic ability and elucidated a regulatory role of OLA1 in promoting chemotherapy resistance of breast cancer. Chemo-sensitivity of the disease can be thus enhanced significantly by knocked down OLA1, which led to the inactivation of the TGF-ß/Smad signaling cascades, polymerized microtubules, and promoted cell apoptosis. Our data suggest that OLA1 may be developed as a potential target to improve chemotherapy of patients with breast cancer.

Metabolic Regulation in Mitochondria and Drug Resistance.

Mitochondria are generally considered as a powerhouse in a cell where the majority of the cellular ATP and metabolite productions occur. Metabolic rewiring and reprogramming may be initiated and regulated by mitochondrial enzymes. The hypothesis that cellular metabolic rewiring and reprogramming processes may occur as cellular microenvironment is disturbed, resulting in alteration of cell phenotype, such as cancer cells resistant to therapeutics seems to be now acceptable. Cancer metabolic reprogramming regulated by mitochondrial enzymes is now one of the hallmarks of cancer. This chapter provides an overview of cancer metabolism and summarizes progress made in mitochondria-mediated metabolic regulation in cancer drug resistance.

A Normotensive Patient with Primary Aldosteronism.

This study was to report a case of normotensive patient with primary aldosteronism who was admitted to our department recently. The patient was a 33-year-old male with right adrenal incidentaloma, but without any symptom. He has no history of hypertension, and blood pressure was normal when measured at multiple time points during hospitalization stay. The 24-hour ambulatory blood pressure prompted a normal blood pressure with the existence of circadian rhythm. The patient was diagnosed with primary aldosteronism by screening and confirmatory test. Due to the absence of symptom, surgery was not preferred. Blood pressure was found to be normal with the 2-month follow-up from discharge until now.

Plasmofluidics: Merging Light and Fluids at the Micro-/Nanoscale.

Plasmofluidics is the synergistic integration of plasmonics and micro/nanofluidics in devices and applications in order to enhance performance. There has been significant progress in the emerging field of plasmofluidics in recent years. By utilizing the capability of plasmonics to manipulate light at the nanoscale, combined with the unique optical properties of fluids and precise manipulation via micro/nanofluidics, plasmofluidic technologies enable innovations in lab-on-a-chip systems, reconfigurable photonic devices, optical sensing, imaging, and spectroscopy. In this review article, the most recent advances in plasmofluidics are examined and categorized into plasmon-enhanced functionalities in microfluidics and microfluidics-enhanced plasmonic devices. The former focuses on plasmonic manipulations of fluids, bubbles, particles, biological cells, and molecules at the micro/nanoscale. The latter includes technological advances that apply microfluidic principles to enable reconfigurable plasmonic devices and performance-enhanced plasmonic sensors. The article is concluded with perspectives on the upcoming challenges, opportunities, and possible future directions of the emerging field of plasmofluidics.

Remote switching of cellular activity and cell signaling using light in conjunction with quantum dots.

Stimulating cells by using light is a non-invasive technique that provides flexibility in probing different locations while minimizing unintended effects on the system. We propose a new way to make cells photosensitive without using genetic or chemical manipulation, which alters natural cells, in conjunction with Quantum Dots (QDs). Remote switching of cellular activity by optical QD excitation is demonstrated by integrating QDs with cells: CdTe QD films with prostate cancer (LnCap) cells, and CdSe QD films and probes with cortical neurons. Changes in membrane potential and ionic currents are recorded by using the patch-clamp method. Upon excitation, the ion channels in the cell membrane were activated, resulting in hyperpolarization or depolarization of the cell.

A facile route to growth of γ-MnOOH nanorods and electrochemical capacitance properties.

Single crystal nanorods of γ-MnOOH with lengths up to hundreds of nanometers were successfully prepared employing a novel solvothermal process based on the redox reaction between potassium permanganate (KMnO(4)) and N, N-dimethyl ammonium formate (DMF) without extra surfactant or template. The as-prepared products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), and Fourier transformed infrared spectroscopy (FTIR). The electrochemical properties of γ-MnOOH nanorods were investigated by cyclic voltammetry and galvanostatic charge-discharge performance measurements. Specific capacitance (C(s)) calculated from the galvanostatic discharge curve was 131.9 F g(-1) for γ-MnOOH nanorods at the current density of 0.5 A g(-1). The electrochemical experiment results demonstrate that γ-MnOOH nanorods should be a good candidate as electrode material for supercapacitor.

Scalable nano-particle assembly by efficient light-induced concentration and fusion.

Avalanche concentration, a rapid, long-range accumulation of particles around a laser spot in a liquid sample, is demonstrated and characterized for various nanoparticles (NPs). The effect is driven by a convective flow in the sample, caused by efficient heating of NPs with high absorption efficiencies. Several types of concentration behavior were observed and characterized. Control of optical power and initial particle density was found to be effective in determining the assembly process. VO(2) nanowires, carbon nanotube (CNT), and quantum dot (QD) electrode gap bridges were assembled with a variety of sizes and geometries to show the utility of the method for nano-assembly. Bridges were assembled from as many as thousands to as few as one NP and were found to form solid electrical contact between the electrodes, as verified by measuring the current--voltage (I-V) characteristic.

Optical manipulation of micron/submicron sized particles and biomolecules through plasmonics.

Plasmonics, a rapidly emerging subdiscipline of nanophotonics, is aimed at exploiting surface plasmons for important applications, including sensing, waveguiding, and imaging. Parallel to these research efforts, technology yielding enhanced scattering and absorption of localized surface plasmons (LSPs) provides promising routes for trapping and manipulation of micro and nano scale particles, as well as biomolecules with low laser intensity due to high energy conversion efficiency under resonant excitation. In this paper, we show that the LSP-induced scattering field from a self-assembled gold nanoparticle array can be used to sustain trapping of single micron-sized particles with low laser intensity. Moreover, we demonstrate for the first time efficient localized concentration of sub-micron sized particles and DNAs of various sizes through photothermal effect of plasmonics.

Synthesis, amino-functionalization of mesoporous silica and its adsorption of Cr(VI).

Mesoporous silica materials with a centered rectangular symmetry (cmm) have been synthesized through a facile direct-templating method using tetraethylorthosilicate (TEOS) and amphiphilic block co-polymers Pluronic P123 under acidic conditions. The amino groups have been grafted to as-synthesized mesoporous silica by [1-(2-amino-ethyl)-3-aminopropyl]trimethoxysilane (AAPTS). Thus obtained amino-functionalized mesoporous silica (denoted as NN-silica) was used for sequestration of Cr(VI) from aqueous solution. After sequestration of Cr(VI), the sample was denoted as Cr(VI)-silica. The parent mesoporous silica, NN-silica and Cr(VI)-silica were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR) and N(2) adsorption-desorption isotherms. XRD and TEM results confirm that the structure of these samples is centered rectangular symmetry (cmm). N(2) adsorption-desorption isotherms show that there is a remarkable decrease in surface area and pore volume for NN-silica (S(BET)=54.5 m(2)g(-1), V(P)=0.09 cm(3)g(-1)) and Cr(VI)-silica (S(BET)=53.2 m(2)g(-1), V(P)=0.07 cm(3)g(-1)) compared to the parent mesoporous silica (S(BET)=444.0 m(2)g(-1), V(P)=0.71 cm(3)g(-1)). The BJH desorption average diameter of NN-silica, Cr(VI)-silica and the parent mesoporous silica is 4.40 nm, 4.07 nm and 5.11 nm, respectively. The results reveal the channels of as-synthesized mesoporous silica are essentially grafted with abundant amino groups and loaded with Cr(VI). The adsorption experiment results show that the functionalized mesoporous silica materials possess an increased Cr(VI) adsorption capacity and the maximum Cr(VI) loadings at 25, 35 and 45 degrees C can reach 2.28, 2.86 and 3.32 mmol/g, respectively.

Low power laser induced microfluidic mixing through localized surface plasmon.

we present a new optical microfluidic mixing approach via surface tension driven force sustained by the localized surface plasmon (LSP) energy. The phonon energy associated with the non-radiative damping of LSP on an Au nanostructure creates thermal gradients capable of actuating a convective fluid flow. Experimental evidence and modeling results both show that LSP from the Au nanostructure is crucial to establish a temperature gradient with sufficient magnitude to induce the convective flow when using a low-power laser source.

Large dielectrophoresis force and torque induced by localized surface plasmon resonance of Au nanoparticle array.

A new approach is proposed for manipulating and rotating micro- or nano-objects by using polarized laser light with low intensity. The polarized light excites resonant dipoles on a cap-shaped Au nanoparticle array, which generates a highly nonuniform radiation field that induces large dielectrophoresis force on dielectric objects. The orientation control of the objects is realized by adjusting the polarization direction of the incident light. Theoretical modeling, fabrication, and characterization results for the cap-shaped Au nanoparticle array, as well as preliminary trapping results, are reported.