Engineering the Structural and Electronic Phases of MoTe2 through W Substitution

MoTe₂ is an exfoliable transition metal dichalcogenide (TMD) that crystallizes in three symmetries: the semiconducting trigonal-prismatic 2H- or α-phase, the semimetallic and monoclinic 1T^'- or β-phase, and the semimetallic orthorhombic γ-structure. The 2H-phase displays a band gap of ∼1 eV making it appealing for flexible and transparent optoelectronics. The γ-phase is predicted to possess unique topological properties that might lead to topologically protected nondissipative transport channels. Recently, it was argued that it is possible to locally induce phase-transformations in TMDs, through chemical doping, local heating, or electric-field to achieve ohmic contacts or to induce useful functionalities such as electronic phase-change memory elements. The combination of semiconducting and topological elements based upon the same compound might produce a new generation of high performance, low dissipation optoelectronic elements. Here, we show that it is possible to engineer the phases of MoTe₂ through W substitution by unveiling the phase-diagram of the Mo_1-xW_xTe₂ solid solution, which displays a semiconducting to semimetallic transition as a function of x. We find that a small critical W concentration x_c ∼ 8% stabilizes the γ-phase at room temperature. This suggests that crystals with x close to x_c might be particularly susceptible to phase transformations induced by an external perturbation, for example, an electric field. Photoemission spectroscopy, indicates that the γ-phase possesses a Fermi surface akin to that of WTe₂.

8-Carboxamidocyclazocine analogues: redefining the structure-activity relationships of 2,6-methano-3-benzazocines

Unexpectedly high affinity for opioid receptors has been observed for a novel series of cyclazocine analogues where the prototypic 8-OH was replaced by a carboxamido group. For mu and kappa opioid receptors, the primary carboxamido derivative of cyclazocine ((+/-)-15) displayed high affinity (Ki=0.41 and 0.53 nM, respectively) nearly comparable to cyclazocine. A high enantiopreference ((2R,6R,11R)-) for binding was also observed. Compound (+/-)-15 also displayed potent antinociception activity in mice when administered icv.

Response to Shiga toxin-1, with and without lipopolysaccharide, in a primate model of hemolytic uremic syndrome

Shiga toxin (Stx) and lipopolysaccharide (LPS) both participate in the pathogenesis of post-diarrheal hemolytic uremic syndrome (HUS), yet little is known about the factors that modulate the host response to these toxins. We have previously shown that the baboon develops HUS if 100 ng/kg of purified Stx-1 is administered rapidly as a single bolus, but not if it is given as four 25-ng/kg doses every 12 h. We therefore used this baboon model to study the response to small intravenous doses of Stx-1, with and without the co-administration of LPS. The co-administration of two 1-mg/kg doses of LPS (given at 0 and 24 h) and four 25-ng/kg doses of Stx-1 (given at 0, 12, 24, and 36 h) resulted in HUS, but the administration of either toxin separately did not. The development of HUS was associated with a rise in urinary, but not plasma concentrations of TNF, and a rise in both urinary and plasma concentrations of IL-6 and IL-8. We speculate that LPS is not required for disease expression in the human, but that it can augment the response to otherwise subtoxic amounts of Stx and this augmentation may be mediated by LPS-induced cytokine release.

3-Carboxamido analogues of morphine and naltrexone. synthesis and opioid receptor binding properties

In response to the unexpectedly high affinity for opioid receptors observed in a novel series of cyclazocine analogues where the prototypic 8-OH was replaced by a carboxamido group, we have prepared the corresponding 3-CONH(2) analogues of morphine and naltrexone. High affinity (K(i)=34 and 1.7nM) for mu opioid receptors was seen, however, the new targets were 39- and 11-fold less potent than morphine and naltrexone, respectively.

Compensated Semimetal LaSb with Unsaturated Magnetoresistance

By combining angle-resolved photoemission spectroscopy and quantum oscillation measurements, we performed a comprehensive investigation on the electronic structure of LaSb, which exhibits near-quadratic extremely large magnetoresistance (XMR) without any sign of saturation at magnetic fields as high as 40 T. We clearly resolve one spherical and one intersecting-ellipsoidal hole Fermi surfaces (FSs) at the Brillouin zone (BZ) center Γ and one ellipsoidal electron FS at the BZ boundary X. The hole and electron carriers calculated from the enclosed FS volumes are perfectly compensated, and the carrier compensation is unaffected by temperature. We further reveal that LaSb is topologically trivial but shares many similarities with the Weyl semimetal TaAs family in the bulk electronic structure. Based on these results, we have examined the mechanisms that have been proposed so far to explain the near-quadratic XMR in semimetals.

Photonic crystal materials and their application in biomedicine

Photonic crystal (PC) materials exhibit unique structural colors that originate from their intrinsic photonic band gap. Because of their highly ordered structure and distinct optical characteristics, PC-based biomaterials have advantages in the multiplex detection, biomolecular screening and real-time monitoring of biomolecules. In addition, PCs provide good platforms for drug loading and biomolecule modification, which could be applied to biosensors and biological carriers. A number of methods are now available to fabricate PC materials with variable structure colors, which could be applied in biomedicine. Emphasis is given to the description of various applications of PC materials in biomedicine, including drug delivery, biodetection and tumor screening. We believe that this article will promote greater communication among researchers in the fields of chemistry, material science, biology, medicine and pharmacy.

Gene expression profiling in developing human hippocampus

The gene expression profile of developing human hippocampus is of particular interest and importance to neurobiologists devoted to development of the human brain and related diseases. To gain further molecular insight into the developmental and functional characteristics, we analyzed the expression profile of active genes in developing human hippocampus. Expressed sequence tags (ESTs) were selected by sequencing randomly selected clones from an original 3'-directed cDNA library of 150-day human fetal hippocampus, and a digital expression profile of 946 known genes that could be divided into 16 categories was generated. We also used for comparison 14 other expression profiles of related human neural cells/tissues, including human adult hippocampus. To yield more confidence regarding differential expression, a method was applied to attach normalized expression data to genes with a low false-positive rate (<0.05). Finally, hierarchical cluster analysis was used to exhibit related gene expression patterns. Our results are in accordance with anatomical and physiological observations made during the developmental process of the human hippocampus. Furthermore, some novel findings appeared to be unique to our results. The abundant expression of genes for cell surface components and disease-related genes drew our attention. Twenty-four genes are significantly different from adult, and 13 genes might be developing hippocampus-specific candidate genes, including wnt2b and some Alzheimer's disease-related genes. Our results could provide useful information on the ontogeny, development, and function of cells in the human hippocampus at the molecular level and underscore the utility of large-scale, parallel gene expression analyses in the study of complex biological phenomena.

[Interactions between domains within the NH2- and COOH-terminal fragments of presenilins]

OBJECTIVE

To analyze the interactions between domains within the NH2- and COOH-terminal regions of presenilins.

METHODS

The various constructions corresponding to NH2-terminal fragment (NTF) and COOH-terminal fragment (CTF) derivatives of presenilin 1 (PS1) and presenilin 2 (PS2) were generated by RT-PCR, and their interactions were assayed by yeast two-hybrid system.

RESULTS

Domains within the NH- and COOH-terminal fragments of presenilins could directly interact with each other, and therefore form high molecular weight complex. The interaction site between domains within PS1 located at amino acid 361-447 of PS1 CTF, without the involvement of other partners. Similar interaction was not observed between PS11-360 and PS2341-448, PS2(1)-340 and PS1(361)-467.

CONCLUSIONS

Intramolecular interaction between domains within the NH2- and COOH-terminal regions of presenilins may be critical to the folding and assembly of mature PS molecules.

[Fragile X mental retardation protein interacts with human NDK/Nm23-H2]

OBJECTIVE

To investigate the physiological role of fragile X mental retardation protein (FMRP) and screen the proteins interacting with FMRP in human fetal hippocampus cDNA library.

METHODS

Human fetal hippocampus cDNA library was constructed in yeast two-hybrid DAD vector pGAD10. Quality of the library was measured by picking up random colonies as templates for PCR testing. Proteins interacting with FMRP were screened by yeast two-hybrid system. Furthermore, the interaction site of FMRP was mapped in yeast.

RESULTS

The average length of inserts of the two-hybrid library was 1.5 kb, and the ratio of recombinant colonies was about 90%. Human NDK/Nm23-H2 was found interacting with FMRP. NDK/Nm23-H2 interacted with FMRP exon 1-12, as well as FMRP isoforms without exon 12, and exons 14-17. NDK/Nm23-H2 couldn't interact with FMRP exon 1-6 and exon 2-7 fragments.

CONCLUSIONS

Human NDK/Nm23-H2 can bind FMRP directly. The interaction site of FMRP is located at its exon 1-11. This interaction in vitro might alter the intracellular distribution of NDK/Nm23-H2, and even regulates the transcription and expression of FMRP.

[Incidence and clinical characteristics of engraftment syndrome after syngeneic hematopoietic stem cell transplantation in patients with hematological diseases]

Objective: To explore the incidence and clinical characteristics of engraftment syndrome (ES) after syngeneic hematopoietic stem cell transplantation (syn-HSCT) in patients with hematological diseases. Methods: The clinical data of 21 patients who received syn-HSCT at People's Hospital of Peking University from January 1994 to May 2018 were retrospectively analyzed. Results: Seven (33.3% ) of 21 patients developed ES. The onset of ES symptoms occurred at a median of 8 (range: 5-13) days after HSCT, and the diagnosis of ES occurred at a median of 10 (range: 7-14) days after HSCT. Steroids were administered immediately after the diagnosis of ES, the median time of symptom continuance was 2 (range: 1-5) days, and all patients showed complete resolution of ES symptoms. In the multivariate analysis, patients with acute myeloid leukemia and faster neutrophil reconstitution were the risk factors for ES (HR=15.298, 95% CI 1.486-157.501, P=0.022, and HR=17.459, 95% CI 1.776-171.687, P=0.014) . Meanwhile, there was no significant difference in the overall survival and disease-free survival between patients with ES and those without ES. Conclusion: A high incidence of ES was observed in syn-HSCT recipients. Moreover, the prognosis of ES was excellent.

[Dose-response association between fluid overload and hospital mortality in patients with sepsis]

Objective: To investigate dose-response associations between fluid overload (FO) and hospital mortality in patients with sepsis. Methods: The current cohort study was prospective and multicenter. Data were derived from the China Critical Care Sepsis Trial, which was conducted from January 2013 to August 2014. Patients aged≥18 years who were admitted to intensive care units (ICUs) for at least 3 days were included. Fluid input/output, fluid balance, fluid overload (FO), and maximum FO (MFO) were calculated during the first 3 days of ICU admission. The patients were divided into three groups based on MFO values: MFO<5%L/kg, MFO 5%-10%L/kg, and MFO≥10% L/kg. Kaplan-Meier analysis was used to predict time to death in hospital in the three groups. Associations between MFO and in-hospital mortality were evaluated via multivariable Cox regression models with restricted cubic splines. Results: A total of 2 070 patients were included in the study, of which 1 339 were male and 731 were female, and the mean age was (62.6±17.9) years. Of 696 (33.6%) who died in hospital, 968 (46.8%) were in the MFO<5%L/kg group, 530 (25.6%) were in the MFO 5%-10%L/kg group, and 572 (27.6%) were in the MFO≥10%L/kg group. Deceased patients had significantly higher fluid input than surviving patients during the first 3 days [7 642.0 (2 874.3, 13 639.5) ml vs. 5 738.0 (1 489.0, 7 153.5)ml], and lower fluid output [4 086.0 (1 367.0, 6 354.5) ml vs. 6 130.0 (2 046.0, 11 762.0) ml]. The cumulative survival rates in the three groups gradually decreased with length of ICU stay, and they were 74.9% (725/968) in the MFO<5% L/kg group, 67.7% (359/530) in the MFO 5%-10%L/kg group, and 51.6% (295/572) in the MFO≥10%L/kg group. Compared with the MFO<5%L/kg group, the MFO≥10%L/kg group had a 49% increased risk of inhospital mortality (HR=1.49, 95%CI 1.28-1.73). For each 1% L/kg increase in MFO, the risk of in-hospital mortality increased by 7% (HR=1.07, 95% CI 1.05-1.09). There was a"J-shaped"non-linear association between MFO and in-hospital mortality with a nadir of 4.1% L/kg. Conclusion: Higher and lower optimum fluid balance levels were associated with an increased risk of in-hospital mortality, as reflected by the observed J-shaped non-linear association between fluid overload and inhospital mortality.

Bethesda system reporting rates, histological follow-up and HPV genotypes distribution of abnormal cytology in Anhui province of China: Analysis of 93,168 cervical liquid-based cytology test reports

OBJECTIVE

To analyze the Bethesda System reporting rates, histological follow-up, and HPV genotypes distribution of abnormal cytology in Anhui province of China.

METHODS

According to the Bethesda Reporting System of Cervical Cytology (2014), a retrospective analysis of the cervical liquid-based cytology (LBC) results, abnormal cytology with concurrent HPV genotype testing, and immediate histological follow-up. HPV genotype testing was performed for 15 High-risk types and 6 Low-risk types. Immediate histological correlation results within 6 months after the LBC and HPV results.

RESULTS

6.70% of women with abnormal LBC results, and ASC/SIL was 1.42. The severe histological results in abnormal cytology were ASC-US (18.58%), ASC-H (53.76%), LSIL (16.62%), HSIL (82.07%), SCC/ACa (100.00%), AGC (63.77%). The total HPV-positive rate in abnormal cytology was 70.29%, of which ASC-US, ASC-H, LSIL, HSIL, SCC/ACa, and AGC were 60.78%, 80.83%, 83.05%, 84.93%, 84.51%, 33.33%. The top three detected genotypes were HR HPV 16, 52, and 58. The most commonly detected genotype in HSIL and SCC/ACa was HPV 16. Of the 91 AGC patients, 34.78% were cervical lesions, and 42.03% were endometrial lesions. The HPV-positive rate in the group of AGC-FN was highest and lowest in the group of AGC-EM.

CONCLUSION

The Bethesda System reporting rates of cervical cytology were all within the benchmark range of the CAP laboratory. HPV 16, 52, and 58 were the most common genotypes in our population, and HPV 16 infection has a higher degree of malignancy of cervical lesions. Among patients with ASC-US results, HPV positive patients had a higher rate of biopsy-detected CIN2+ than HPV negative patients.

[Association between fluid balance and clinical outcomes in sepsis patients with identified subtypes]

Objective: To identify clinical subphenotypes of sepsis by clinical variables, and the association between fluid balance (FB) and outcomes in sepsis patients with different subphenotypes. Methods: Data were derived from China Critical Care Sepsis Trial. A total of 2 075 patients were included in the study, with a mean age of (62.5±17.4) years, 1 362 (65.6%) were male, 713 (34.3%) were female. In-hospital mortality was the primary outcome. Clinical variables were entered into the latent profile analysis (LPA) model which was used to identify the subphenotypes of sepsis. Multivariable logistic regression model was used to explore the association of FB on the first 2 days admitted to ICU and in-hospital mortality. Results: Total of 687 (33.1%) patients died in the hospital. Four subphenotypes of sepsis were identified by the PLA model: 1 421 (68.5%) patients were identified as profile 1, which was characterized by the lowest in-hospital mortality (28.3%, 402/1 421) and was considered as the baseline subphenotype; profile 2 was characterized by multiple organ dysfunction(232, 11.2%); profile 3 was characterized by respiratory dysfunction (196, 9.4%) and profile 4 was characterized by kidney injury/failure (226, 10.9%). Profile 2 showed the highest in-hospital mortality (54.3%, 126/232), followed by profile 4 (39.4%, 89/226), profile 3 (35.7%, 70/196). Profile 2 had the highest FB of 68.5(34.7, 89.4)ml/kg on day 1 and decreased rapidly to 29.4(13.6, 49.8) ml/kg on day 2. Multivariable analysis showed that for every 10 ml/kg of FB increased on the first 48 hours admitted to ICU, the risk of in-hospital mortality decreased 14% (OR=0.86, 95%CI: 0.81-0.97) in profile 2, and increased 4% (OR=1.04, 95%CI:1.02-1.07) in profile 4. However, there were no significant association between FB on the fist 2 days admitted to ICU and the risk of in-hospital mortality in profile 1 (OR=1.06, 95%CI: 0.94-1.19)and in profile 3 (OR=0.99, 95%CI: 0.94-1.05). Conclusions: Four subphenotypes of sepsis were identified according to the clinical variables, which showed different characteristics, distributions, outcomes and responses to fluid balance.

[Analyses of the risk factors of delayed extubation after extended thymectomy in patients with myasthenia gravis]

Objective: To explore the risk factors of delayed extubation after expanded thymectomy in patients with myasthenia gravis. Methods: Patients with myasthenia gravis who underwent expanded thymectomy from May 2021 to January 2024 and were admitted to Intensive Care Unit (ICU) after surgery were retrospectively analyzed. Patients were divided in to the delayed extubation and successful extubation according to the length of mechanical ventilation whether exceeding than 48 hours. Multivariable logistics regression was used to explore the risk factors for delayed extubation after expanded thymectomy in patients with myasthenia gravis. Results: A total of 95 patients were included.15 (15.8%) of whom were delayed extubation. Compared with the successful extubation patients, the length of mechanical ventilation (94.0 h vs. 15.5 h, P<0.001), ICU station (7.1 days vs. 1.7 days, P<0.001), and hospitalization station (16.0 days vs. 9.1 days, P<0.001) were significantly prolonged in the delayed extubation patients. Adjusted for age,gender, BMI, clinical classification, pathological classification of thymoma, dose of pyridostigmine preoperative, perioperative pneumonia, preoperative pulmonary dysfunction, SBT passing for the first time, neck lift time greater than 20 seconds, the multivariable logistic regression shown, the risk of delayed extubation increased by 29% (OR=1.290, 95%CI 1.090-1.714), 1% (OR=1.009, 95%CI 1.002-1.034), 3.9-fold (OR=4.977, 95%CI 1.486-10.939), and 64% (OR=1.635, 95%CI 1.396-2.682) for every 60 mg/day increase in preoperative dose of pyridostigmine, pathological classification of thymoma, perioperative pneumonia, and preoperative pulmonary dysfunction, respectively. Neck lift time greater than 20 seconds can reduce the risk of delayed extubation 48% (OR=0.524, 95%CI 0.322-0.794). Conclusion: Preoperative administration of a large dose of pyridostigmine, pulmonary dysfunction, pathological classification of thymoma, and perioperative pneumonia were risk factors for delayed extubation after thymectomy in these patients. And neck lift time greater than 20 seconds decreased the risk of delayed extubation. In the clinical practice,for high risk of MG patients with delayed extubation, the neck lifting test may be used to assess muscle strength and reduce the occurance of tracheal reintubation and its advise effects.

[Association between onset time of sepsis-associated acute kidney injury and clinical outcome in patients with sepsis]

Objective: To explore the relationship between the onset time of sepsis-associated acute kidney injury (SA-AKI) and adverse clinical outcomes. Methods: Data were derived from Beijing Acute Kidney Injure Trial (BAKIT) which investigated the epidemiology of acute kidney injury (AKI) in critically ill patients at 30 intensive care units (ICU) of 28 tertiary hospitals in Beijing from 1 March to 31 August 2012. Patients who were older than 18 years and diagnosed with sepsis and AKI, and expected to stay in ICU for at least 24 h were included in this study. A total of 653 patients were included in this study, 414 males and 239 females with a mean age of (68.2±17.0) years. According to the onset time of SA-AKI, patients were grouped into early AKI (E-AKI) (AKI occurred within 48 hours after ICU admission) and late AKI (L-AKI) (AKI occurred after 48 hours of ICU admission) group. The primary outcome was major adverse kidney events (MAKE), consisted of all-cause mortality, renal replacement therapy-dependence, and an inability to recover to 1.5 times of the baseline creatinine value up to 30 days. Multivariable logistic regression was used to investigate the association between the onset time of SA-AKI and clinical outcomes. Results: A total of 653 patients with SA-AKI were included, 423 (64.8%) patients developed E-AKI, 230 (35.2%) cases developed L-AKI, MAKE occurred in 405 (62.0%) cases, and 301 (46.1%) patients died in hospital. Compared with E-AKI group, L-AKI patients showed higher AKI 3 level rate [55.7%(128/230) vs 40.2%(170/423), P<0.001], incidence of MAKE [72.6%(167/230) vs 56.3%(238/423,P<0.001)] and hospital mortality [55.2%(127/230) vs 44.1%(174/423), P=0.001]. The risk of MAKE and in-hospital mortality in L-AKI group increased for 2.55-fold times (OR=3.55, 95%CI: 1.94-6.04) and 1.84-fold times (OR=2.84, 95%CI: 1.44-5.60) when compared with those in E-AKI, respectively (both P<0.05). Conclusion: Late timing onset of SA-AKI is associated with poor clinical outcomes.