ABSTRACT
Chirality is a fascinating geometrical concept with widespread applications in biology, chemistry, and materials. Incorporating chirality into hybrid perovskite materials can induce novel physical properties (chiral optical activity, nonlinear optics, etc.). Hybrid lead-free or lead-substituted perovskite materials, as representatives of perovskites, have been widely used in fields such as photovoltaics, sensors, catalysis, and detectors. However, the successful introduction of chirality into hybrid lead-free perovskites, which can enable their potential applications in areas such as circularly polarized light photodetectors, memories, and spin transistors, remains a challenging research topic. Here, we synthesized two new chiral lead-free perovskites, [(R)-2-methylpiperazine][BiI5] and [(S)-2-methylpiperazine][BiI5]. The material possesses a perovskite structure with a one-dimensional (1D) arrangement, denoted as ABX5. This structure is composed of chiral cations, specifically methylpiperazine, and endless chains of [BiI3] along the a-axis. These chains are assembled from distorted coplanar [BiI5]2- octahedra. The testing results revealed that (R)-1 and (S)-1 have narrow band gaps (Eg-R = 2.016 eV, Eg-S = 1.964 eV), high photoelectric response, and long carrier lifetime [R = 4.94 µs (τ), S = 7.85 µs (τ)]. It is worth noting that 1D chiral lead-free perovskites (R)-1 and (S)-1, which are synthesized in this study with narrow band gaps, high photoelectric response, and long carrier lifetime, have the potential to serve as alternative materials for the perovskite layer in future iterations of lead-free perovskite solar cells. Moreover, this research will inspire the preparation of multifunctional, lead-free perovskites.
ABSTRACT
Two novel luminescent metal-organic frameworks (MOFs), [Zn3(TCA)2(BPB)2]n (DZU-101, where H3TCA = 4,4',4''-tricarboxyltriphenylamine and BPB = 1,4-bis(pyrid-4-yl)benzene) and [Zn3(TCA)2(BPB)DMA]n (DZU-102), based on the same ligands and metal ions were synthesized by regulating the amount of water in the solvothermal reaction system. Structural analyses show that the two MOFs have pillar-layered frameworks with Zn3 clusters connected by the TCA3- and BPB ligands. Interestingly, DZU-102 possessed a two-fold interpenetrated framework distinct from the individual network of DZU-101. As a result, DZU-102 showed a visual fluorescence color change from chartreuse to azure in m-xylene, while the fluorescence color was turquoise in p-/o-xylene with no change. Furthermore, compared with p/o-xylene, the fluorescence emission peak of DZU-102 in m-xylene suspension produced an obvious blue shift. Moreover, selective fluorescence sensing experiments were also carried out, which demonstrated that the degree of peak shift was related to the concentration of m-xylene, indicating the potential application of DZU-102 in fluorescence sensing of m-xylene from xylene isomers and further revealed the application of structural interpenetration for luminescence tuning of MOFs.
ABSTRACT
PURPOSE: To delineate the clinical and genetic characteristics of Chinese patients with RPGRIP1-associated Leber congenital amaurosis 6 (LCA6). METHODS: After screening 352 unrelated families with clinically diagnosed RP, five LCA6 patients with RPGRIP1 variations from unrelated Chinese families were identified. Full ophthalmology examinations, including decimal best-corrected visual acuity (BCVA), fundus photography, fundus autofluorescence imaging, spectral-domain optical coherence tomography (SD-OCT), full-field electroretinography (ffERG), multifocal electroretinography (mfERG), perimetry, and flash visual evoked potential (FVEP), were performed. Target next-generation sequencing (NGS) and Sanger sequencing were performed for the five patients to identify and to validate candidate disease-causing variants. RESULTS: Five patients were molecularly diagnosed as the LCA6 associated with RPGRIP1 variation, with typical clinical characteristics including congenital night blindness, nystagmus, and visual defect, at an early age. Interestingly, LCA6 exhibited extensive clinical heterogeneity and the changes in the morphology and function were not completely consistent in the five LCA6 patients. Case 1 showed extensive inferior-nasal retinal atrophy with a corresponding area of hypofluorescence in fundus autofluorescence, and the fundus photograph was nearly normal in cases 2 and 3. The ERG results displayed a moderately reduced rod-system response in cases 1 and 2 and a significant reduced rod-system response in case 3. Both case 4 and case 5 showed mottled pigmentation in fundi and an unrecordable rod and cone-system response in ERG. Moreover, we identified eight compound variants and one homozygous variant in the five patients with RPGRIP1. CONCLUSIONS: This is the largest report focused on the clinical electrophysiological features of patients with associated LCA6 caused by the variation in the RPGRIP1 gene in the Chinese population with an enriched phenotypic and genotypic background of LCA6 to improve future gene therapies.
ABSTRACT
BACKGROUND AND AIMS: Through a retrospective study of maternal near miss (MNM) cases treated by the Suqian Critical Maternal Care Center in Suqian City, Jiangsu Province, we summarized the most common diseases that caused MNM, treatment measures, and short-term prognosis in this region. The purpose of the research is to improve the clinical evidence of maternal health care in the region. METHODS: The study is a retrospective descriptive study. Among the pregnant women admitted to the Critical Maternal Care Center from 1 January 2015, to 31 December 2019, the pregnant women with severe pregnancy complications or comorbidities were identified as the research subjects. The study subjects were divided into an MNM group and a control group according to the MNM criteria recommended by the WHO.A retrospective analysis of the study subject data, including causes and clinical manifestations of MNM, treatment measures, and short-term prognosis, was conducted. RESULTS: The total number of deliveries was 27 619. There were 145 women in the control group and 65 women in the MNM group. The number of MNM cases accounted for 2.4% (65/27619) of the total number of deliveries. Placenta previa, postpartum hemorrhage, and hypertension accounted for 72.3% (47/65) of the causes of MNM cases observed. In the MNM group, the most common clinical manifestation was bleeding (80.0%, 52/65). Sixty-three patients underwent massive blood transfusion (96.9%, 63/65), and 36 underwent hysterectomy (55.4%,36/65). The prevalence of interventional procedures and unplanned secondary operations in the MNM group was higher than that in the control group. CONCLUSIONS: The top three causes of MNM were placenta previa, postpartum hemorrhage, and hypertension in pregnancy in Suqian area. Sufficient blood sources, convenient and fast blood transfusion procedures, and the use of large amounts of blood transfusion technology have an important impact on the success of treatment. Hysterectomy is still the main method of MNM treatment.
ABSTRACT
BACKGROUND: To investigate the prevalence of nosocomial infections, the distribution of nosocomial infection sites, the use of antibiotic and the situation of detected nosocomial infection pathogens in the Inner Mongolia Autonomous Region of China from 2012 to 2014, to grasp the current conditions of regional nosocomial infections in timely, for the development of infection prevention and control measures to provide a basis for effective hospital. METHODS: A survey of the prevalence of nosocomial infections was conducted in target hospitals using the combination of a bedside survey and medical record review. RESULTS: In total, 101,907 inpatients were surveyed from 2012 to 2014. There were 1,997 cases of nosocomial infections, accounting for an average prevalence of 1.96%. The infection site was mainly the lower respiratory tract. Higher prevalence of nosocomial infections occurred in the comprehensive intensive care unit (ICU), Neurosurgery Department, and Hematology Department. The average rate of antibiotic use was 33.72%, and the average submission rate for bacterial cultures for patients who received therapeutic treatment with antibiotics was 28.26%. The most common pathogens associated with nosocomial infections were Gram-negative (G(-)) bacteria, and frequently detected bacterial pathogens included Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Acinetobacter baumannii, and Staphylococcus aureus. CONCLUSIONS: The survey of the prevalence of nosocomial infections helped to identify problems in the control process of nosocomial infections and to develop targeted measures for the prevention and control of these infections accordingly.
ABSTRACT
OBJECTIVE: To study the status of hospital infection management staff of the Inner Mongolia Autonomous Region. METHODS: The respondents completed the unified questionnaire. The person entered into the computer after checking, using EXCEL software for analysis. RESULTS: This survey involved 341 hospital infection management staffs, with an average age of 41.59 years. Professional background in nursing accounted for 59.53%. Bachelor degree or above accounted for 52.20%.The number of senior professional titles accounted for 40.47%. 78.09% of the staffs did not involve in the research. 36.58% of the staffs had special training or experience to lecture. Received provincial and national professional training staff accounted for 41.08% and 13.62%. Never received professional training in management of hospital infection accounted for 27.70%. 59.95% of the staff was never participated in academic exchanges. CONCLUSION: The hospital should give appropriate preferential treatment to the hospital infection management department in term of introduction of talent, job promotion, research, conference expenses and so on. Construction of a high-quality management team to improve the hospital infection management in our region.
