Choroid plexus immune cell response in murine hydrocephalus induced by intraventricular hemorrhage.

BACKGROUND: Intraventricular hemorrhage (IVH) and associated hydrocephalus are significant complications of intracerebral and subarachnoid hemorrhage. Despite proximity to IVH, the immune cell response at the choroid plexus (ChP) has been relatively understudied. This study employs CX3CR-1GFP mice, which marks multiple immune cell populations, and immunohistochemistry to outline that response. METHODS: This study had four parts all examining male adult CX3CR-1GFP mice. Part 1 examined naïve mice. In part 2, mice received an injection 30 µl of autologous blood into right ventricle and were euthanized at 24 h. In part 3, mice underwent intraventricular injection of saline, iron or peroxiredoxin 2 (Prx-2) and were euthanized at 24 h. In part 4, mice received intraventricular iron injection and were treated with either control or clodronate liposomes and were euthanized at 24 h. All mice underwent magnetic resonance imaging to quantify ventricular volume. The ChP immune cell response was examined by combining analysis of GFP(+) immune cells and immunofluorescence staining. RESULTS: IVH and intraventricular iron or Prx-2 injection in CX3CR-1GFP mice all induced ventriculomegaly and activation of ChP immune cells. There were very marked increases in the numbers of ChP epiplexus macrophages, T lymphocytes and neutrophils. Co-injection of clodronate liposomes with iron reduced the ventriculomegaly which was associated with fewer epiplexus and stromal macrophages but not reduced T lymphocytes and neutrophils. CONCLUSION: There is a marked immune cell response at the ChP in IVH involving epiplexus cells, T lymphocytes and neutrophils. The blood components iron and Prx-2 may play a role in eliciting that response. Reduction of ChP macrophages with clodronate liposomes reduced iron-induced ventriculomegaly suggesting that ChP macrophages may be a promising therapeutic target for managing IVH-induced hydrocephalus.

Deep learning radiomics on shear wave elastography and b-mode ultrasound videos of diaphragm for weaning outcome prediction.

PURPOSE: We proposed an automatic method based on deep learning radiomics (DLR) on shear wave elastography (SWE) and B-mode ultrasound videos of diaphragm for two classification tasks, one for differentiation between the control and patient groups, and the other for weaning outcome prediction. MATERIALS AND METHODS: We included a total of 581 SWE and B-mode ultrasound videos, of which 466 were from the control group of 179 normal subjects, and 115 were from the patient group of 35 mechanically ventilated subjects in the intensive care unit (ICU). Among the patient group, 17 subjects successfully weaned and 18 failed. The deep neural network of U-Net was utilized to automatically segment diaphragm regions in dual-modal videos of SWE and B-mode. High-throughput radiomics features were then extracted, the statistical test and least absolute shrinkage and selection operator (LASSO) were applied for feature dimension reduction. The optimal classification models for the two tasks were established using the support vector machine (SVM). RESULTS: The automatic segmentation model achieved Dice score of 87.89 %. A total of 4524 radiomics features were extracted, 10 and 20 important features were left after feature dimension reduction for constructing the two classification models. The best areas under receiver operating characteristic curves of the two models reached 84.01 % and 94.37 %, respectively. CONCLUSIONS: Our proposed DLR methods are innovative for automatic segmentation of diaphragm regions in SWE and B-mode videos and deep mining of high-throughput radiomics features from dual-modal images. The approaches have been proved to be effective for prediction of weaning outcomes.

Examining the impact of spatial accessibility to rehabilitation facilities on the degree of disability: A heterogeneity perspective.

The positive effect of healthcare facilities on residents' health has been extensively studied. However, few studies have focused on the role of rehabilitation services as unique healthcare services for persons with disabilities. This study aimed to examine the relationship between the spatial accessibility of rehabilitation facilities and the degree of disability. To this end, an approach of measuring the spatial accessibility of rehabilitation facilities to persons with disabilities was proposed. This approach integrates multiple key elements including the characteristics of facilities (i.e., the capacity, frequency of use and service radius), characteristics of the mobility of persons with disabilities (i.e., the mode of travel, escort support, transportation fee and barrier-free environment requirements) and travel time obtained from a routing application programme interface. The accessibility of rehabilitation facilities was calculated at the neighbourhood level within the Central Urban Area of Tianjin Municipality. The ordinal logistic regression analysis revealed that higher accessibility to rehabilitation facilities generally corresponded to lower severity of disability. However, the impact varied depending on the type of disability. Increased accessibility was associated with greater severity of intellectual disability, whereas it was linked to reduced severity of visual, hearing, limb, mental and speech disabilities. It is suggested to incorporate disability diversity and the accessibility of rehabilitation facilities into spatial planning and governance.

Machine learning-enabled regional multi-hazards risk assessment considering social vulnerability.

The regional multi-hazards risk assessment poses difficulties due to data access challenges, and the potential interactions between multi-hazards and social vulnerability. For better natural hazards risk perception and preparedness, it is important to study the nature-hazards risk distribution in different areas, specifically a major priority in the areas of high hazards level and social vulnerability. We propose a multi-hazards risk assessment method which considers social vulnerability into the analyzing and utilize machine learning-enabled models to solve this issue. The proposed methodology integrates three aspects as follows: (1) characterization and mapping of multi-hazards (Flooding, Wildfires, and Seismic) using five machine learning methods including Naïve Bayes (NB), K-Nearest Neighbors (KNN), Logistic Regression (LR), Random Forest (RF), and K-Means (KM); (2) evaluation of social vulnerability with a composite index tailored for the case-study area and using machine learning models for classification; (3) risk-based quantification of spatial interaction mechanisms between multi-hazards and social vulnerability. The results indicate that RF model performs best in both hazard-related and social vulnerability datasets. The most cities at multi-hazards risk account for 34.12% of total studied cities (covering 20.80% land). Additionally, high multi-hazards level and socially vulnerable cities account for 15.88% (covering 4.92% land). This study generates a multi-hazards risk map which show a wide variety of spatial patterns and a corresponding understanding of where regional high hazards potential and vulnerable areas are. It emphasizes an urgent need to implement information-based prioritization when natural hazards coming, and effective policy measures for reducing natural-hazards risks in future.

Nano-selenium enhances sugarcane resistance to Xanthomonas albilineans infection and improvement of juice quality.

Selenium is an important trace element that is beneficial to human health and can enhance plant resistance and crop quality. The occurrence of up-to-date nanotechnology greatly promotes the beneficial efficiency of this trace element on crops. The discovery of nano-Se increased the crop quality and reduced plant disease in different plant. In this study, we reduced sugarcane leaf scald disease incidence by exogenously spraying different concentrations (5 mg/L and 10 mg/L) of nano-Se. Additional studies revealed that spraying of nano-Se reduced reactive oxygen species (ROS) and H2O2 accumulation, and increased antioxidant enzyme activities in sugarcane. The nano-selenium treatments also increased the content of jasmonic acid (JA) and the expression of JA pathway genes. Furthermore, we also found that use nano-Se treatment in an appropriate way can enhance the quality of cane juice. The brix of the cane juice of the selenium-enriched treatment was significantly higher than that of the control group, which was 10.98% and 20.81% higher than that of the CK group, respectively. Meanwhile, the content of certain beneficial amino acids was increased, with the highest being 3.9 times higher than the control. Taken together, our findings inferred that nano-Se could act as a potential eco-fungicide to protect sugarcane from can be used as a potential ecological bactericide to protect sugarcane from Xanthomonas albilineans infections, and improve sugarcane quality. The results arising from this study not only introduces an ecological method to control X. albilineans, but also provides a deep insight into this trace elements for improving juice quality.

The prognostic value of the Charlson comorbidity index in aged patients with intracerebral hemorrhage.

BACKGROUND: Comorbidities are common in aged intracerebral hemorrhage patients. The purpose of this study was to assess whether the Charlson Comorbidity Index (CCI) was associated with in-hospital death and short-term functional outcome in elderly patients (age ≥ 70) with intracerebral hemorrhage (ICH). METHODS: This was a retrospective cohort of aged ICH patients (≥70 years old) admitted within 24 hours of ICH onset. The CCI was derived using hospital discharge ICD-9 CM codes and patient history obtained from standardized case report forms. Multivariable logistic regression was used to determine the independent effect of the CCI score on clinical outcomes. RESULTS: In this cohort of 248 aged ICH patients, comorbid conditions were common, with CCI scores ranging from 2 to 12. Logistic regression showed that the CCI score was independently predictive of 1-month functional outcome (OR = 1.642, P < 0.001) and in-hospital death (OR = 1.480, P = 0.003). Neither ICH volume nor the presence of IVH was an independent predictive factor for 1-month functional outcome or in-hospital mortality (P < 0.05). CONCLUSION: Comorbid medical conditions as assessed by the CCI independently influence short-term outcomes in aged ICH patients. The characteristics of the hematoma itself, such as ICH volume and the presence of IVH, seem to have a reduced effect on it.

[Temporal and spatial evolution of regional cultural landscape under the influence of construction land expansion: A case study of Hanjiang delta in Guangdong, China.] / å»ºè®¾ç”¨åœ°æ‰©å¼ å¯¹åŒºåŸŸæ–‡åŒ–æ™¯è§‚æ—¶ç©ºæ¼”å˜çš„å½±å“­­ä»¥å¹¿ä¸œçœéŸ©æ±Ÿä¸‰è§’洲为例.

Cultural landscapes are the products of combination of natural and human factors with constant change in response to human behavior. Exploring the impacts of construction land expansion on cultural landscapes is the key to understand the formal connotations and value characteristics of human activities interfering with cultural landscapes. In this study, we first classified the cultural landscape of the Hanjiang Delta and then used the landscape index to quantitatively describe the spatial and temporal evolution characteristics of the cultural landscape from 1980 to 2018. Finally, we analyzed the spatial effect between construction land expansion and the cultural landscape with a spatial panel econometric model. The results showed that a total of seven cultural landscape types were identified at the regional level. From 1980 to 2000, the cultural landscape pattern in the study area changed substantially, with increasing fragmentation, deepening irregularity, and increasing diversity. The proportion of regional construction land increased from 14.8% to 29.9%. The year 2000 was the cut-off point for the rate of construction land expansion, and the chronological characteristics of cultural landscape change coincided with it. There was a spatial dependency between the expansion of construction land and the change of cultural landscape. With the expansion of construction land, the sprawl town landscape in sand dike became the dominant type, and the paddy scattered historical villages, the wetland agglomeration town landscape, and the paddy wetland landscape in net river lowland faced extinction. Construction land expansion affected the local landscape pattern and had spatial spillover effects on neighboring areas. For a particular landscape type, the expansion of construction land led to a general increase in the degree of patch integration and an enhanced landscape agglomeration effect. For different types, this led to a decrease in inter-landscape sprawl, an increase in patch irregularity, and enhanced fragmentation. This study could provide a reference for the human history inheritance and ecological pattern optimization in the Hanjiang Delta.

"Atypical" Mild Clinical Presentation in Elderly Patients With Ruptured Intracranial Aneurysm: Causes and Clinical Characteristics.

Objective: Thunderclap-like severe headache or consciousness disturbance is the common "typical" clinical presentation after aneurysmal subarachnoid hemorrhage (aSAH); however, a slowly developing "atypical" clinical pattern, with mild headache, vomiting, or dizziness, is frequently noted in elderly patients. The aim of this study was to evaluate the clinical characteristics of this "atypical" subgroup, as well as related factors associated with the presence of these mild symptoms. Methods: The data of 176 elderly patients (≥70 years old) with ruptured intracranial aneurysms (IAs) treated at our center from January 2016 to January 2020 were retrospectively collected and analyzed. The patients were divided into "typical" and "atypical" groups based on their initial and development of clinical symptoms after the diagnosis of aSAH. Intergroup differences were analyzed, and factors related to the presence of these two clinical patterns were explored through multiple logistic regression analyses. Results: Despite significant admission delay (P < 0.001) caused by mild initial symptoms with slow development, patients in the "atypical" group achieved better clinical prognosis, as indicated by a significantly higher favourable outcome ratio and lower death rate upon discharge and at different time points during the 1-year follow-up, than the "typical" group (P < 0.05). Multiple logistic regression analysis revealed that modified Fisher grade III-IV (OR = 11.182, P = 0.003), brain atrophy (OR = 10.010, P = 0.001), a larger lesion diameter (OR = 1.287, P < 0.001) and current smoking (OR = 5.728, P < 0.001) were independently associated with the presence of "typical" symptoms. Aneurysms with wide necks (OR = 0.013, P < 0.001) were independently associated with the presence of "atypical" symptoms. Conclusions: "Atypical" presentations, with mild clinical symptoms and slow development, were commonly recorded in elderly patients after the onset of aSAH. Despite the prolonged admission delay, these "atypical" patients achieved better clinical outcomes than those with "typical" symptoms. Modified Fisher grade (III-IV), current smoking, brain atrophy and larger lesion diameter were factors predictive of "typical" symptoms, while aneurysms with wide necks were independently associated with "atypical" symptoms.

Single-Cell RNA Sequencing Reveals the Pathogenic Relevance of Intracranial Atherosclerosis in Blood Blister-Like Aneurysms.

Background: Intracranial non-branching site blood blister-like aneurysms (BBA) are extremely rare and vicious. Their etiology remains elusive, and no molecular study has been carried out to reveal its pathogenic relevance to intracranial atherosclerosis. To investigate its transcriptomic landscape and underlying potential pathogenesis, we performed single-cell RNA sequencing with extensive pathological validation. Methods: In total, 12,245 cells were recovered for single-cell RNA sequencing analysis from 1 BBA and 2 saccular intracranial aneurysms (IAs). Unbiased clustering using Seurat-based pipeline was used for cellular landscape profiling. Cellchat was used to understand intracellular communications. Furthermore, 10 BBAs and 30 IAs were retrospectively collected for pathological validations like scanning electron microscopy, H&E stain, Masson stain, Verhoeff Van Gielson stain, and immunofluorescence. Results: Single-cell transcriptome profiled 14 total subclusters in 6 major groups, namely, 6 monocyte/macrophage clusters, 2 T&NK clusters, 3 vascular smooth muscle cell (VSMC) clusters, 1 dendritic cell, 1 B cell, and 1 endothelial cell cluster. The only mural cell identified in BBAs was VSMC-2 cluster, while mural cells in IAs comprise most clusters of VSMCs and endothelial cells. Upregulated genes in BBA-derived VSMCs are related to arterial mineralization and atherosclerosis, such as PTX3, SPP1, LOX, etc., whereas vasodilation and physiological regulatory genes such as MGP, ACTA2, and MYL9 were conversely enriched in conventional IA-derived VSMCs. Immune cells in the BBA were predominantly macrophages, with a low fraction of T&NK cells, while conventional IAs had a higher percentage of T&NK. Gene enrichment analysis suggested that macrophages in BBA were highly enriched in lipid metabolism as well as atherosclerosis. Ligand-receptor interaction suggested that secretory phosphoprotein 1 (also known as osteopontin) played a major role in mediating the intracellular communication between VSMC and macrophages, especially in BBA. Pathological experiments corroborate with the bioinformatic findings and further characterized BBAs as a thin-walled thrombotic aneurysm with severe atherosclerotic lesions, where ApoE+ macrophages and OPN+ mural cells are intimately involved in the inflammation process. Conclusions: The preexisting intracranial atherosclerosis might predispose the parent artery to the pathogenic occurrence of BBAs. These data shed light on the pathophysiology of intracranial aneurysms and might assist in the further resolution of the complexity in aneurysm pathogenesis.

A new method for broadening the detection range of immunoassay and its application in ß-hCG quantitative detection.

Early pregnancy prediction requires very high ß-hCG detection sensitivity, while embryonic development monitoring and trophoblastic disease detection require a wider detection range. In this study, based on light-initiated chemiluminescence assay (LICA), one high-affinity mAb and one low-affinity mAb were selected and coated on chemibeads with a larger coating area in different ratios to immobilize the antibodies. The two immobilized mAbs were mixed with different concentrations to detect ß-hCG. When the high-affinity mAb-coated chemibeads and low-affinity mAb-coated chemibeads were used at working concentrations of 0.100 mg mL-1 and 0.014 mg mL-1, respectively, the sensitivity and detection range were maximized. The assay was precise for measuring ß-hCG with repeatability and intermediate precision of <5% CV. The assay has a high sensitivity with a limit of quantification (LoQ) of 0.49 IU L-1, which is lower than that of most ß-hCG detection kits. Over the range of 1 IU L-1 to 16 000 IU L-1, the assay had a proper linearity (r = 0.9995). No false negative results due to the hook effect were observed at ß-hCG concentrations up to 225 000 IU L-1. The assay showed a good correlation with the Abbott assay (r = 0.9910). LICA combined with immobilized mAbs with different affinities ensures the sensitivity of ß-hCG detection and broadens the detection range.

Evidence-based nursing intervention can improve the treatment compliance, quality of life and self-efficacy of patients with lung cancer undergoing radiotherapy and chemotherapy.

OBJECTIVE: To investigate the improvement effect of evidence-based nursing intervention on treatment compliance, quality of life and self-efficacy of patients with lung carcinoma (LC) undergoing radiotherapy and chemotherapy. METHODS: From May 2018 to August 2019, 183 patients with LC who received radiotherapy and chemotherapy in our hospital were selected and divided into two groups in accordance with different nursing methods. Among them, 85 patients who received routine nursing intervention were included in the control group (CG), and 98 patients who received evidence-based nursing intervention were included in the research group (RG). The improvement of pulmonary function indexes [(FVC), forced expiratory volume in one second (FEV1), ratio of forced expiratory volume in one second to forced vital capacity (FEV1/FVC)] was observed before and after nursing. The pain degree was evaluated by the visual analogue scale (VAS). The treatment compliance between groups was compared. The psychological emotions of the patients were evaluated by a self-rating anxiety scale (SAS) and a self-rating depression scale (SDS). The General Self-efficacy Scale (GSES) was applied to assess the self-efficacy and the Quality of Life (SF-36) scale was applied to evaluate the quality of life. The incidence of secondary infection was observed in the two groups. The nursing satisfaction was evaluated by a nursing satisfaction questionnaire made by our hospital. RESULTS: After nursing, the improvement of FEV1, FVC and FEV1/FVC levels in the RG were obviously better than that in the CG; The scores of VAS, SAS and SDS and total incidence of secondary infection in the RG were obviously lower than those in the CG; The treatment compliance, GSES and SF-36 scores, and nursing satisfaction scores of patients in the RG were obviously higher than that in the CG. CONCLUSION: Evidence-based nursing intervention can improve treatment compliance, lung function, self-efficacy and quality of life for patients with LC undergoing radiotherapy and chemotherapy.

Mesenchymal Stem Cells Decrease M1/M2 Ratio and Alleviate Inflammation to Improve Limb Ischemia in Mice.

BACKGROUND Limb ischemia (LI) is the underlying pathology of peripheral artery disease (PAD). Macrophages play a critical role in inflammation and can contribute to the exacerbation or reduction of inflammation. Transplantation of mesenchymal stem cells (MSCs) is an emerging therapeutic strategy for PAD. However, the mechanism by which human placenta-derived mesenchymal stem cells (PMSCs) regulate macrophage differentiation in ischemic tissue remains unclear. MATERIAL AND METHODS Placentas were obtained from healthy donors with normal 38- to 40-week gestation, and PMSCs were isolated from the placentas and cultured. A mouse model of hind-limb ischemia was established. Ischemic limbs were injected intramuscularly with about 5×106 PMSCs in the PMSCs group or a placebo solution (phosphate-buffered saline) in the control group at 4 different sites 1 day after the procedure. The blood perfusion of hind-limbs and the histological morphology were observed at day 1, 7, and 14 after the surgical procedure. Macrophages were detected by flow cytometry. The expression of serum tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-6, and IL-10 were detected by enzyme-linked immunosorbent assay (ELISA). The expression of CD31 and smooth muscle alpha-actin (alpha-SMA) in frozen muscle samples were detected by immunofluorescence staining. RESULTS In the PMSCs group, blood perfusion was gradually recovered and ischemic injury was markedly alleviated. The percentage of M2-like macrophages was increased dramatically, while the M1/M2 macrophage ratio was reduced. The expression of TNF-alpha and IL-6 was reduced, while the IL-10 level was elevated. The expression and density of CD31- and alpha-SMA-positive vessels were both significantly increased. CONCLUSIONS Transplanted PMSCs alleviated inflammation, promoted neovascularization, and improved hind limb ischemia through regulating macrophage differentiation toward the M2 phenotype and cytokine secretion. Cytokine manipulation of macrophage phenotypes may have potential therapeutic benefits in injured ischemic limbs.

Is excited state intramolecular proton transfer frustrated in 10-hydroxy-11H-benzo[b]fluoren-11-one?

Recently, Piechowska and coworker found that hydroxybenzofluorenone 10-hydroxy11H-benzo[b]fluoren-11-one (10-HHBF) does not show dual fluorescence, which is in contrast to its well-known analogue 1-hydroxy-11H-benzo[b]fluoren-11-one (1-HHBF) [Dyes Pigm. 2019, 165, 346-353.]. Based on the increased donor-acceptor distance and the lower stability of the excited state tautomer of former, they believe that different from 1-HHBF, ESIPT is not occurring in 10-HHBF. In the preset work, in order to clarify whether ESIPT would take place in 10-HHBF, we have optimized the four-state geometrical structures (ground state S0, first singlet excited state S1, transition state S1-TS and after proton transfer S1-PT), carried out the Natural Population Analysis and scanned the ground-state and excited-state potential energy curves of 1-HHBF and 10-HHBF at TD-CAM-B3LYP/6-311 + g(2d,2p)/IEFPCM (cyclohexane) theory level. It is found that ESIPT should take place in both 1-HHBF and 10-HHBF and the Gibbs free energy diagram further indicates that the ESIPT process is more favorable in 10-HHBF than in 1-HHBF.

Association of single nucleotide polymorphisms in the 3'UTR region of TPM1 gene with dilated cardiomyopathy: A case-control study.

Tropomyosin 1 (TPM1) is a protein that constitutes the sarcomere filaments and is encoded by the TPM1 gene. The aim of the present study is to investigate the correlation between the 3' untranslated region (3'UTR) single nucleotide polymorphisms (SNPs) of the TPM1 gene and dilated cardiomyopathy (DCM).A total of 245 patients with DCM and 245 healthy controls were recruited with 5 ml of venous blood. Genomic DNA was extracted to analyze the TPM1 gene rs12148828, rs11558748, rs707602, rs6738, rs7178040 loci genotypes, and the plasma miR-21 level was analyzed by reverse transcription-PCR (RT-PCR).The risk of DCM development in the rs6738 locus G allele carriers were 1.69 times more than A allele carriers (95% CI: 1.22-2.33, P = .001). Age and gender had no effect on the association of TPM1 gene SNPs with DCM risk (P > .05). The plasma miR-21 level of TPM1 gene rs6738 locus AA carriers was significantly higher than that of the AG and GG genotypes (P < .001).The SNPs of TPM1 gene rs6738 locus is associated with the risk of DCM, which may be related to the abnormal increase of miR-21 level in DCM patients, but further research is needed to prove the causal relationship between miR-21 level and DCM risk.

Application of real-time shear wave elastography in the assessment of torsional cervical dystonia.

BACKGROUND: This study aimed to investigate the value of real-time shear wave elastography (SWE) in the assessment of torsional cervical dystonia (TCD). METHODS: Ninety healthy volunteers and 30 TCD patients were recruited, and elastography was performed at musculi sternocleidomastoideus (MSD) and musculi splenius capitis (MSC). Mean shear elastic modulus of right MSD and MSC in healthy controls and bilateral MSD and MSC in TCD patients was determined. The thickness of MSD and MSC of affected muscles was measured in TCD patients. RESULTS: In TCD patients, the mean shear elastic modulus of affected MSD and MSC was significantly higher than that of corresponding normal muscles (P<0.01) and that of controls (P<0.01). The diagnostic threshold was 24.9 kPa for MSD and 25.07 kPa for MSC (for MSD and MSC, the area under ROC was 0.979 and 0.979, with a sensitivity of 90% and 91.3%, and a specificity of 95.6% and 96.7%, respectively). The elastic modulus of neither affected nor normal MSD and MSC was significantly related to age and body mass index (P>0.05). The shear elastic modulus of affected MSD and MSC was positively related to the peak electromyography (r=0.83-0.73, P<0.01). The thickness of affected MSD and MSC was significantly thicker than that of corresponding normal muscles in TCD patients (P<0.01). CONCLUSIONS: Real-time SWE can identify the difference in shear elastic modulus of MSD and MSC between the affected and normal side in TCD patients, indicating important diagnostic value in the assessment of muscular status for these patients.

Investigation of the intramolecular hydrogen bonding interactions and excited state proton transfer mechanism for both Br-BTN and CN-BTN systems.

In the present work, two novel Br-BTN and CN-BTN compounds have been investigated theoretically. We in-depth explore the excited state hydrogen bonding interactions and the excited state intramolecular proton transfer (ESIPT) behaviors for the Br-BTN and CN-BTN system. We firstly verify the formation of hydrogen bond effects of O-H⋯N based on reduced density gradient (RDG) versus sign(λ 2)ρ. The simulated primary bond lengths and bond angles as well as infrared (IR) vibrational spectra reveal that the hydrogen bond O-H⋯N should be strengthened in the excited state. Combining the frontier molecular orbital (MO) investigations, we infer that the charge transfer phenomenon (from HOMO to LUMO) around hydrogen bonding moieties reveals the tendency of ESIPT reaction. Particularly, the increased electronic densities around proton acceptor atoms facilitate attracting a hydrogen proton, which plays a decisive role in opening the ESIPT reaction. Via constructing potential energy curves in both S0 and S1 states, the ultrafast ESIPT process can be verified which explains previous experimental characteristics. Furthermore, via searching the transition state (TS) structure and constructing the intrinsic reaction coordinate (IRC) reaction path, we check and confirm the ESIPT mechanism for both Br-BTN and CN-BTN systems. We sincerely hope that our theoretical work could guide novel applications based on Br-BTN and CN-BTN compounds in future.

Electronic and magnetic properties of a black phosphorene/Tl2S heterostructure with transition metal atom intercalation: a first-principles study.

Using density functional theory calculations, the structural, electronic and magnetic properties of a black phosphorene/Tl2S heterostructure (BP/Tl2S) and the BP/Tl2S intercalated with transition metal atoms (TMs) have been detailed investigated. It is demonstrated that the BP/Tl2S is a type-I van der Waals (vdW) heterostructure with an indirect band gap of approximately 0.79 eV. The BP/Tl2S experiences a transition from type-I to type-II when various strains are applied. In addition, the BP/Tl2S intercalated with TMs (TM-BP/Tl2S) exhibits various kinds of meaningful electronic and magnetic properties. Several TM-BP/Tl2S systems are still non-magnetic ground states and six TM-BP/Tl2S (Ti-, V-, Cr-, Mn-, Fe-, Tc-) systems are ferromagnetic. Interestingly, three TM-BP/Tl2S (V-, Cr-, Mn-) systems display half-metallic character. The Fe-BP/Tl2S and Tc-BP/Tl2S are dilute magnetic semiconductors (DMSs), while TM-BP/Tl2S (Mo-, Pd-, Ni-) systems are semiconductors. The other TM-BP/Tl2S systems become metals. These results may open a new avenue for application of the BP/Tl2S in future spintronic and electronic devices.

Excited state hydrogen bond and proton transfer mechanism for (2­hydroxy­4­methoxyphenyl)(phenyl)­methanone azine: A theoretical investigation.

A novel fluorescence molecule (2­hydroxy­4­methoxyphenyl)(phenyl)­methanone azine (HMPM) has been explored theoretically in this present work. Based on density functional theory (DFT) and time-dependent density functional theory (TDDFT) methods, we investigate the excited state hydrogen bonding behaviors and excite state intramolecular proton transfer (ESIPT) process for HMPM molecule. Via simulating the reduced density gradient (RDG) versus sign(λ2)ρ, we firstly verify the double intramolecular hydrogen bonds (O1H2⋯N3 and O4H5⋯N6) for HMPM system. Comparing with the changes about these two hydrogen bonds (i.e., bond distances, bond angles and infrared (IR) vibrational spectra), we find that they should be enhanced in the first excited state upon the photo-excitation. The shortened hydrogen bonding distance of H2⋯N3 and H5⋯N6 provide the possibility for ESIPT reaction. Given the photo-excitation process, we confirm the charge redistribution around the hydrogen bonding moieties plays an important role as a driving force for the ESIPT process. Further, via constructing S0-state and S1-state potential energy surfaces (PESs), we confirm the excited state double proton transfer (ESDPT) is excludable since the high optimized energy and high potential energy barrier. While the low potential barrier for excited state single proton transfer path results in the ultrafast ESIPT reaction, which explains why the initial HMPM fluorescence peak cannot be detected in previous experimental phenomenon. This work not only clarifies the excited state dynamical behavior for HMPM system, but also explains previous experimental phenomenon and attributions about steady state spectra. We hope this work can facilitate novel applications based on the novel HMPM system in future.

Metallic VO2 monolayer as an anode material for Li, Na, K, Mg or Ca ion storage: a first-principle study.

Using density functional theory (DFT), we assess the suitability of monolayer VO2 as promising electrode materials for Li, Na, K, Mg and Ca ion batteries. The metallic VO2 monolayer can offer an intrinsic advantage for the transportation of electrons in materials. The results suggest that VO2 can provide excellent mobility with lower diffusion barriers of 0.043 eV for K, 0.119 eV for Li, 0.098 eV for Na, 0.517 eV for Mg, and 0.306 eV for Ca. The specific capacities of Li, Na and Mg can reach up to 968, 613 and 815 mA h g-1 respectively, which are significantly larger than the corresponding value of graphite. Herein, with high open-circuit voltage the VO2 sheet could be a promising candidate for the anode material in battery applications.

Theoretical research on excited-state intramolecular proton coupled charge transfer modulated by molecular structure.

At the TD-B3LYP/TZVP/IEFPCM theory level, we have theoretically studied the excited-state intramolecular proton coupled charge transfer (ESIPCCT) process for both 4'-N,N-diethylamino-3-hydroxyflavone (3HFN) and 2-{[2-(2-hydroxyphenyl)benzo[d]oxazol-6-yl]methylene}malononitrile (diCN-HBO) molecules. Our calculated hydrogen bond lengths and angles sufficiently confirm that the intramolecular hydrogen bonds O1-H1⋯O2 and O1-H1⋯N1 formed at the S0 states of 3HFN and diCN-HBO should be significantly strengthened in the S1 state, which is further supported by the results obtained based on the analyses of infrared spectra shifts, molecular orbitals and charge density differences maps. The significant strengthening of intramolecular hydrogen bonds O1-H1⋯O2 and O1-H1⋯N1 upon photoexcitation should facilitate the ESIPCCT process of the two title molecules. The scanned potential energy curves and confirmed excited-state transition states for both 3HFN and diCN-HBO show that the proton can be easily transferred from O1 to O2 (N1 for diCN-HBO) through the strengthened intramolecular hydrogen bonds upon photoexcitation to the S1 state.