Tailoring a Two-Dimensional Halide Perovskite Composed of the Secondary Amine Cation for Anisotropic X-ray Responses.

Two-dimensional (2D) metal-halide perovskites have shown broad application prospects in the field of optoelectronic detection. The presence of the natural quantum-well structure results in strong anisotropy of physical properties, while studies on anisotropic X-ray responses remain insufficient. Here, we present an intriguing anisotropy of X-ray-responsive behaviors in a 2D halide perovskite, (t-ACH)2(DMA)Pb2Br7 (1, where t-ACH is trans-4-(aminomethyl)cyclohexanecarboxylate and DMA is dimethylamine), in which the secondary amine DMA+ cation with a large ionic radius locates inside the perovskite cage to form inorganic frameworks. The alternative alignment of inorganic slabs and organic bilayers creates a typical quantum-well architecture, which accounts for the generation of photoelectronic anisotropy. High-quality crystals of 1 exhibit notable semiconducting properties with a large µτ product (1.9 × 10-4 cm2 V-1). Intriguingly, 1 has better X-ray detection sensitivity (∼569.9 µC Gyair-1 cm-2) along the in-plane direction, which is attributed to its excellent charge carrier transport performance in this direction. Conversely, the higher resistance stemming from the organic barrier results in a lower detection limit along the out-of-plane direction (∼78.1 nGyair s-1), much lower than the medical diagnostic criteria (∼5.5 µGyair s-1). This work might open up new possibilities for the creative use of hybrid perovskites in direct X-ray detection.

The Effect of Hemoglobin Concentration on Hyperbaric Oxygen and Non-hyperbaric Oxygen in the Treatment of Hypertensive Intracerebral Hemorrhage After Operation at the High Altitude.

Background: The prognosis of hypertensive intracerebral hemorrhage (HICH) is poor at high altitudes. The objective of this study was to explore whether hyperbaric oxygen (HBO) can improve the results of computed tomography perfusion (CTP) imaging and the neurological function of patients with HICH, and influence the hemoglobin concentration. Method: The patients with HICH were treated with puncture and drainage. Twenty-one patients (51.22% of 41 patients in total) were treated with HBO after the operation, and the other patients received conventional treatment. CTP was performed twice, and all indices were measured. Scatter plots were used to determine the effect of hemoglobin concentration on CTP imaging. Receiver operating characteristic (ROC) curves were plotted to analyze the effects of hemoglobin concentration and hematoma volume on recovery results. The patients were followed up for 6 months. Results: Forty-one patients with HICH were treated with puncture and drainage. In total, 21 were treated with HBO after the operation, and 20 received conventional treatment as the control group. No significant differences in the CBV and CBF values of the two groups were noted before treatment. After 10 days, the values of CBV and CBF in the HBO group were significantly higher than those in the control group. A scatter diagram showed there was no significant in the HBO group, but significant correlation for the CBV and CBF values in the control group's hematoma center and margin. The ROC curves showed that hematoma volume had an influence on prognosis of the control group. The Glasgow Coma Scale (GOS) scores of the HBO group were significantly higher than those of the control group (p < 0.05). Conclusions: HBO therapy can improve the postoperative CBV and CBF values of patients with HICH and ameliorate their prognoses. There was no significant correlation between HBO group and hemoglobin concentration on admission.

The effect of hematoma puncture drainage before decompressive craniectomy on the prognosis of hypertensive intracerebral hemorrhage with cerebral hernia at a high altitude.

PURPOSE: Rapid decompressive craniectomy (DC) was the most effective method for the treatment of hypertensive intracerebral hemorrhage (HICH) with cerebral hernia, but the mortality and disability rate is still high. We suspected that hematoma puncture drainage (PD) + DC may improve the therapeutic effect and thus compared the combined surgery with DC alone. METHODS: From December 2013 to July 2019, patients with HICH from Linzhi, Tibet and Honghe, Yunnan Province were retrospectively analyzed. The selection criteria were as follows: (1) altitude ≥1500 m; (2) HICH patients with cerebral hernia; (3) Glascow coma scale score of 4-8 and time from onset to admission ≤3 h; (4) good liver and kidney function; and (5) complete case data. The included patients were divided into DC group and PD + DC group. The patients were followed up for 6 months. The outcome was assessed by Glasgow outcome scale (GOS) score, Kaplan-Meier survival curve and correlation between time from admission to operation and prognosis. A good outcome was defined as independent (GOS score, 4-5) and poor outcome defined as dependent (GOS score, 3-1). All data analyses were performed using SPSS 19, and comparison between two groups was conducted using separate t-tests or Chi-square tests. RESULTS: A total of 65 patients was included. The age ranged 34-90 years (mean, 63.00 ± 14.04 years). Among them, 31 patients had the operation of PD + DC, whereas 34 patients underwent DC. The two groups had no significant difference in the basic characteristics. After 6 months of follow-up, in the PD + DC group there were 8 death, 4 vegetative state, 4 severe disability (GOS score 1-3, poor outcome 51.6 %); 8 moderate disability, and 7 good recovery (GOS score 4-5, good outcome 48.4 %); while in the DC group the result was 15 death, 6 vegetative state, 5 severe disability (poor outcome 76.5 %), 4 moderate disability and 4 good recovery (good outcome 23.5 %). The GOS score and good outcome were significantly less in DC group than in PD + DC group (Z = -1.993, p = 0.046; χ2 = 4.38, p = 0.043). However, there was no significant difference regarding the survival curve between PD + DC group and DC group. The correlation between the time from admission to operation and GOS at 6 months (r = -0.41, R2 = 0.002, p = 0.829) was not significant in the PD + DC group, but significant in the DC group (r = -0.357, R2 = 0.128, p = 0.038). CONCLUSION: PD + DC treatment can improve the good outcomes better than DC treatment for HICH with cerebral hernia at a high altitude.

Rescuing Dicer expression in inflamed colon tissues alleviates colitis and prevents colitis-associated tumorigenesis.

Chronic inflammation is known to promote carcinogenesis; Dicer heterozygous mice are more likely to develop colitis-associated tumors. This study investigates whether Dicer is downregulated in inflamed colon tissues before malignancy occurs and whether increasing Dicer expression in inflamed colon tissues can alleviate colitis and prevent colitis-associated tumorigenesis. Methods: Gene expression in colon tissues was analyzed by immunohistochemistry, immunoblots, and real-time RT-PCR. Hydrogen peroxide or N-acetyl-L-cysteine was used to induce or alleviate oxidative stress, respectively. Mice were given azoxymethane followed by dextran sulfate sodium to induce colitis and colon tumors. Berberine, anastrozole, or pranoprofen was used to rescue Dicer expression in inflammatory colon tissues. Results: Oxidative stress repressed Dicer expression in inflamed colon tissues by inducing miR-215 expression. Decreased Dicer expression increased DNA damage and cytosolic DNA and promoted interleukin-6 expression upon hydrogen peroxide treatment. Dicer overexpression in inflamed colon tissues alleviated inflammation and repressed colitis-associated carcinogenesis. Furthermore, we found that anastrozole, berberine, and pranoprofen could promote Dicer expression and protect cells from hydrogen peroxide-induced DNA damage, thereby reducing cytosolic DNA and partially repressing interleukin-6 expression upon hydrogen peroxide treatment. Rescuing Dicer expression using anastrozole, berberine, or pranoprofen in inflamed colon tissues alleviated colitis and prevented colitis-associated tumorigenesis. Conclusions: Dicer was downregulated in inflamed colon tissues before malignancy occurred. Decreased Dicer expression further exaggerated inflammation, which may promote carcinogenesis. Anastrozole, berberine, and pranoprofen alleviated colitis and colitis-associated tumorigenesis by promoting Dicer expression. Our study provides insight into potential colitis treatment and colitis-associated colon cancer prevention strategies.

Hemoglobin Concentration May Affect the Effect of Atorvastin on Chronic Subdural Hematoma After Burr-Hole Drainage at High Altitude.

OBJECTIVE: Chronic subdural hematoma (CSDH) is a common disease. Atorvastatin calcium can increase CSDH absorption. However, whether atorvastatin can increase hematoma absorption and reduce recurrence at high altitudes is not clear. METHODS: After burr-hole drainage, CSDH patients were divided into an atorvastatin group and a control group. Follow-up computed tomography (CT) was performed on day 1, months 1, 2, and 3 after surgery. Then, the recurrence rate, poor therapeutic effect, time to recurrence, poor surgical result, recurrence with operation, CSDH volume, and Markwalder grading scale score (MGSS) were calculated, and related risk factors were analyzed. RESULTS: The non-recurrent and recurrent patients in the control group differed significantly in terms of the hemoglobin concentration (HB) [176.24 ± 16.43 vs. 194.25 ± 12.34 (g/L), p < 0.01], CT value [41.92 ± 10.76 vs. 34.12 ± 8.78 (Hu), p < 0.01], and low-density time [3.88 ± 1.04 vs. 5.50 ± 0.87 (d), p < 0.01]. The non-recurrent and recurrent patients in the atorvastatin group differed significantly in terms of the HB [172.66 ± 16.41 vs. 190.45 ± 10.23 (g/L), p < 0.01], CT value [38.91 ± 7.16 vs. 29.50 ± 8.61 (Hu), p < 0.01], and mixed [2 vs. 4 (n), p < 0.05] and low-density time [4.09 ± 0.75 vs. 5.45 ± 1.12 (d), p < 0.01]. The logistic regression analysis showed that HB [odds ratio, 1.14; 95% confidence interval (CI), 1.04-1.25 in the control group, odds ratio, 1.13; 95% CI, 1.03-1.23 in the atorvastatin group] and low-density time (odds ratio, 3.53; 95% CI, 1.42-8.74 in the control group, odds ratio, 2.53; 95% CI, 1.10-5.80 in the atorvastatin group) were possible risk factors for the two groups. The receiver operating characteristic curves showed that the area under the receiver operating characteristic curve values for the HB, CT value (Hu), and low-density time were 0.812, 0.702, and 0.755 for all subjects; 0.812, 0.719, and 0.790 for the control group; and 0.807, 0.682, and 0.756 for the atorvastatin group, respectively. The postoperative follow-up results showed that there was no significant difference in the recurrence rate, poor therapeutic effect, time to recurrence, poor surgical result, recurrence with operation, CSDH volume, or MGSS between the two groups. CONCLUSION: The effect of atorvastatin was not significant after the operation. The risk factors for CSDH recurrence were the HB and low-density time. The HB was the most specific and sensitive predictor of CSDH recurrence.

Analysis of different hematoma expansion shapes caused by different risk factors in patients with hypertensive intracerebral hemorrhage.

OBJECTIVE: To elucidate the relationship between the risk factors and hematoma expansion(HE)shapes. PATIENTS AND METHODS: From February 2013 to November 2018, 60 patients diagnosed as basal ganglia ICH were divided into the filled type hematoma expansion group (FTE group) and the expanded type hematoma expansion group (ETE group). we performed follow-up CT and three-dimensional reconstruction for the patients and compared the hematoma before and after the expansion of size and extent. RESULTS: The regression analysis showed that the irregular sign (odds ratio, 3.64; 95 % CI, 1.46-9.12), black hole sign (odds ratio, 3.85; 95 % CI, 1.40-10.60), blend sign (odds ratio, 2.86; 95 % CI, 1.03-7.95), and early use of dehydration (odds ratio, 4.59; 95 % CI, 1.59-13.19) were possible risk factors for the ETE group, while the high systolic blood pressure (odds ratio, 1.51; 95 % CI, 1.04-2.30), early use of dehydration (odds ratio, 3.27; 95 % CI, 1.10-9.69) and low density low-density band (odds ratio, 4.52; 95 % CI, 1.54-13.28) were possible risk factors for the FTE group. CONCLUSIONS: The irregular sign, black hole sign, blend sign and early use of dehydration may be the main risk factors for ETE, whereas early use of dehydration, high systolic blood pressure, and low density low-density band may be the main risk factors for FTE.

Complement C3 participates in the function and mechanism of traumatic brain injury at simulated high altitude.

BACKGROUND: Traumatic brain injury (TBI) leads to severe mortality and disability, in which secondary injury induced by complement activation plays an important role. TBI tends to be associated with more severe cerebral edema and worse neurological functional recovery if it occurs in high-altitude areas than in low-altitude areas. However, the underlying mechanism of this difference is unknown. Thus, we used cobra venom factor (CVF) to deplete complement C3 in simulated high-altitude areas to explore whether the differences in outcome at different altitudes are related to secondary injury caused by complement C3. METHODS: The weight-drop model was adopted to induce TBI in rats. Rats were randomly divided into the following groups: sham + saline (sham), high altitude + TBI + saline (HAT), high altitude + TBI + CVF (H-CVF), low altitude + TBI + saline (LAT), and low altitude + TBI + CVF (L-CVF). Brain contusion and edema volumes, brain water content, myelin basic protein (MBP) expression, tumor necrosis factor alpha (TNF-a) expression, interleukin 1 beta (IL1B) expression, mortality rate, neurological function, and complement component 3 (C3) mRNA expression were measured by techniques such as Evans blue fluorescence, Perls staining, TUNEL staining, ELISA, immunohistochemistry and Western blotting to evaluate correlations between complement activation and secondary injury. RESULTS: The activation of complement after TBI was significantly higher at high altitude than at low altitude. High-altitude TBI resulted in a leakier blood-brain barrier, more severe cerebral edema and higher mortality than low-altitude TBI did. In addition, high-altitude TBI tended to be associated with more MBP degradation, ferric iron deposition, neuronal apoptosis, and inflammatory factor deposition than low-altitude TBI. All of these effects of TBI were partially reversed by inhibiting complement activation using CVF. CONCLUSION: Our study provided evidence that TBI at high altitude leads to severe edema and high mortality and disability rates. Complement C3 activation is one of the important factors contributing to secondary brain injury.

Hemoglobin Concentration Affects Hypertensive Basal Ganglia Hemorrhage After Surgery: Correlation Analysis in a High-Altitude Region.

OBJECTIVE: Hypertensive cerebral hemorrhage leads to greater mortality and worse functional outcomes at high altitudes. Experimental studies have suggested that hemoglobin can lead to increased perihemorrhagic edema after intracerebral hemorrhage. METHODS: Patients were divided into a high-hemoglobin (H-H) group (>180 g/L) and a low-hemoglobin (L-H) group (≤180 g/L). The distance from the cortex to the midline was used to indicate the degree of edema. At 1, 7, 14, and 21 days, the patients' status was scored using the Glasgow coma scale, and survival was plotted using Kaplan-Meier survival curves. Pearson correlation analysis showed that the difference between the postoperative and preoperative Glasgow coma scale score correlated with the hemoglobin concentration. The Glasgow outcome scale was used to assess neurological recovery after 6 months. RESULTS: On days 7, 14, and 21, the edema of the H-H group was significantly greater than that of the L-H group (P < 0.01 and P < 0.001, respectively). The edema of the H-H group peaked at 14 and 21 days, but that of the L-H group peaked at 7 days. The hemoglobin concentration and postoperative neurological recovery had a linear relationship in the H-H group. The L-H group had greater survival compared with the H-H group (P < 0.05). The L-H group had higher Glasgow outcome scale scores compared with the H-H group (P < 0.05). CONCLUSION: The hemoglobin concentration affects the mortality and morbidity from hypertensive cerebral hemorrhage in high-altitude regions, and a linear relationship exists between hemoglobin concentration and neurological recovery in the H-H group.

MicroRNA-34a promotes MICB expression in hepatocytes.

MicroRNA-34a (miR-34a) behaves as a tumor suppressor by decreasing the expression of oncogenes involved in multiple carcinogenic pathways. Intravenous delivery of miR-34a mimics has been investigated in clinical trials as a potential treatment for advanced cancers; however, the effect of miR-34a on cancer immune surveillance is controversial. In the current study, we found that miR-34a plays a dual role in the regulation of major histocompatibility complex class I-related sequence B (MICB) protein, a ligand of the NKG2D receptor. MiR-34a could both induce and reduce MICB expression by upregulating ataxia telangiectasia and Rad3-related (ATR) protein kinase and downregulating the transcription factor E2F1, respectively. The net effect of miR-34a on MICB expression depended on endogenous E2F1 levels. Overexpression of miR-34a promoted MICB expression in hepatocytes and hepatocellular carcinoma (HCC) cells that have low E2F1 levels but not in HCC cells that have high E2F1 levels. In HCC patients, the expression of miR-34a and MICB showed positive correlation in paratumor liver tissues, which have low E2F1 levels, but not in HCC tissues, which have high E2F1 levels. We showed that miR-34a overexpression in non-transformed liver cells enhanced cytolysis and interferon-γ production by NK-92MI cells. Furthermore, higher miR-34a expression in tumor and paratumor tissues was associated with positive and negative outcomes, respectively, in HCC patients. Our findings suggest that miR-34a induces MICB expression in paratumor liver tissues, which may cause liver damage and serious cytokine release syndrome, thus disclosing potential side effects of systemic administration of miR-34a in anticancer therapy.

Application of a Grading System in the Treatment of Frontal Lobe Contusion in High-Altitude Regions.

OBJECTIVE: With the development of frontal contusion, patients may rapidly deteriorate or even die. Experience in the treatment of frontal contusion in high-altitude regions is limited; thus, we explore a grading system for the treatment of frontal lobe contusion. METHODS: A total of 446 patients with frontal contusions in a high-altitude regions were reviewed retrospectively. We combined the patients' computed tomography scans of the head and clinical features for grading. The score determined the treatment and whether the bone flap was removed. If the patient's condition deteriorated, and the score was greater than 1, the patient was treated surgically. At the same time, the risk factors of deterioration were analyzed. Finally, the Glasgow Outcome Scale of conservative treatment and surgical treatment groups was analyzed. RESULTS: Among the 446 patients, 254 were conservatively treated, and 28 worsened and underwent surgical treatment. In total, 122 patients received an operation. Logistic regression analysis indicated that scattered hematoma, anterior angle of the ventricle, and hemoglobin concentration were risk factors. The postoperative Glasgow Outcome Scale of conservative treatment and surgical treatment groups was analyzed; the good healing rate of the conservative treatment group was 91.12%, the good healing rate of the retain-bone flap surgical group was 75%, and the good healing rate of the remove-bone flap surgical group was 63.33%. The failure rates of the groups were 9.38% and 7.78%, respectively. CONCLUSIONS: This grading system could guide frontal contusion treatment, which could help patients to achieve a good healing rate and reduce the failure rate.

Simvastatin Reduces Neutrophils Infiltration Into Brain Parenchyma After Intracerebral Hemorrhage via Regulating Peripheral Neutrophils Apoptosis.

Statins, known for their lipid-lowering effects, also have immunomodulatory properties. This study aims to examine whether systematic simvastatin administration could decrease polymorphonuclear neutrophils (PMNs) infiltration into brain tissue, as well as alleviate neuroinflammation in a rat model of intracerebral hemorrhage (ICH). The ICH model was induced in adult male Sprague-Dawley rats by an injection of autologous blood. Animals randomly received simvastatin (i.p. 2 mg/kg) or vehicle daily from 5 days before ICH until sacrificed. Routine blood counts, brain water content, neurological scoring, immunofluorescence and RT-PCR were conducted to evaluate the anti-inflammatory effect of simvastatin following ICH. Furthermore, flow cytometric and western blotting analysis were implemented for elucidating the mechanisms involved in simvastatin-induced reduction of neutrophil brain-invading. Elevated PMNs count and neutrophil-to-lymphocyte ratio in circulation were detected in rat model of ICH, which was reversed by using simvastatin. Simvastatin effectively alleviated PMNs infiltration and proinflammatory factors release in perihematomal area, as well as attenuated ICH-induced brain edema and neurological deficits. Simvastatin significantly downregulated the expression of antiapoptotic protein-Mcl-1 while increased the level of proapoptotic protein-Bax and cleaved caspase 3 in PMNs. Simvastatin treatment significantly alleviated PMNs brain-infiltrating and subsequent neuroinflammatory reaction after ICH, in part by accelerating peripheral PMNs apoptosis through disorganized the expression of apoptotic related proteins. Our data provided new evidence for simvastatin application on patients with ICH.

A case of Galen vein thrombosis occurring after bilateral acetabular fractures in the Tibet plateau - what can we learn?

Hypoxia leads to increased red blood cells and blood viscosity at high altitude while moderate trauma increases coagulation in blood. Under the above-mentioned conditions, venous sinus thrombosis is more likely to occur. A patient suffering bilateral acetabular fractures together with the gradual disturbance of consciousness was admitted to our hospital. Though computed tomography arteriogram (CTA) of the brain displayed normal blood vessels; bilateral thalamus and brainstem infarction were found on head computed tomography (CT) and Galen vein thrombosis on cerebral computed tomography venography (CTV). Dehydration and tracheotomy were immediately conducted with antiplatelet, anticoagulant and neurotrophic medicine administered to the patient. After three days' treatment, the patient's consciousness gradually improved and eventually became clear enough to leave the hospital. On follow-up, no dysfunction was documented.

Endovascular treatment of distal posterior inferior cerebellar artery aneurysms.

OBJECTIVE: To assess the feasibility and results of endovascular treatment for ruptured distal posterior inferior cerebellar artery (PICA) aneurysms. METHODS: We retrospectively reviewed our experience and results with endovascular treatments for a series of 13 consecutive patients with ruptured distal PICA aneurysms at the Southwest Hospital, Chongqing, China, treated between June 2011 and January 2015. Therapeutic considerations, intraoperative complications, and results were evaluated. RESULTS: Endovascular embolization was performed in all 13 patients including selective coiling (4), stentassisted coiling (2), microcatheter-assisted coiling (1), coiling without adjunctive techniques (1), and parent artery occlusion (5). Planed stent deployment failure occurred in one patients resulting from marked stenosis at the origin of the PICA; the patient`s existing partial Wallenberg`s syndrome became worse after treatment. Another 2 patients treated with parent artery occlusion recovered well without developing obvious neurological deficits, although a small cerebellar infarction of the distal PICA was observed. No patient experienced post procedural hemorrhage during the follow-up period (8-46 months; mean, 26.8 months). CONCLUSION: Distal PICA aneurysms can be managed effectively with various endovascular methods. Protective strategies using a stent or microcatheter for preserving the patency of the proximal PICA segment are a viable treatment option in reducing the potential risk of brain stem ischemia in selected patients.

Elevated Hemoglobin Concentration Affects Acute Severe Head Trauma After Recovery from Surgery of Neurologic Function in the Tibetan Plateau.

BACKGROUND: Long-lived inhabitants of the plateau region have a higher hemoglobin concentration, which is the leading cause of damage in various organs, especially the nervous system. The aim of this study was to investigate the effect of hemoglobin concentration on mortality and neural functions after decompressive craniectomy in patients with hypoxia. METHODS: Patients with acute severe head trauma were classified into an elevated hemoglobin concentration group (EHb) and a moderate hemoglobin concentration group (MHb). The survival rate was evaluated by comparing the Glasgow Coma Score on days 1, 3, 7, and 15 after surgery (Kaplan-Meier survival curve). The Glasgow Outcome Scale classification method was used to evaluate recovery of neural function. RESULTS: The Glasgow Coma Score scores on days 3, 7, and 15 were lower in the EHb group compared with the MHb group (P < 0.05). Mortality was significantly higher in the EHb group compared with the MHb group (P < 0.05). After 6 months, the Glasgow Outcome Scale of the MHb group was significantly higher than that of the EHb group (P < 0.05). CONCLUSIONS: Elevated hemoglobin concentration has a serious impact on neurologic recovery and mortality, as seen in patients with acute severe head trauma after decompressive craniectomy.