Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 303
Filter
1.
Science ; 385(6704): 91-99, 2024 Jul 05.
Article in English | MEDLINE | ID: mdl-38963839

ABSTRACT

Sickle cell disease (SCD) is a prevalent, life-threatening condition attributable to a heritable mutation in ß-hemoglobin. Therapeutic induction of fetal hemoglobin (HbF) can ameliorate disease complications and has been intently pursued. However, safe and effective small-molecule inducers of HbF remain elusive. We report the discovery of dWIZ-1 and dWIZ-2, molecular glue degraders of the WIZ transcription factor that robustly induce HbF in erythroblasts. Phenotypic screening of a cereblon (CRBN)-biased chemical library revealed WIZ as a previously unknown repressor of HbF. WIZ degradation is mediated by recruitment of WIZ(ZF7) to CRBN by dWIZ-1, as resolved by crystallography of the ternary complex. Pharmacological degradation of WIZ was well tolerated and induced HbF in humanized mice and cynomolgus monkeys. These findings establish WIZ degradation as a globally accessible therapeutic strategy for SCD.


Subject(s)
Anemia, Sickle Cell , Antisickling Agents , Fetal Hemoglobin , Kruppel-Like Transcription Factors , Nerve Tissue Proteins , Animals , Humans , Mice , Adaptor Proteins, Signal Transducing/metabolism , Adaptor Proteins, Signal Transducing/genetics , Anemia, Sickle Cell/drug therapy , Anemia, Sickle Cell/metabolism , Antisickling Agents/chemistry , Antisickling Agents/pharmacology , Antisickling Agents/therapeutic use , Crystallography, X-Ray , Drug Discovery , Fetal Hemoglobin/genetics , Fetal Hemoglobin/metabolism , Kruppel-Like Transcription Factors/metabolism , Macaca fascicularis , Nerve Tissue Proteins/metabolism , Proteolysis/drug effects , Small Molecule Libraries/chemistry , Small Molecule Libraries/pharmacology , Small Molecule Libraries/therapeutic use , Ubiquitin-Protein Ligases/metabolism , Ubiquitin-Protein Ligases/genetics
2.
Article in English | MEDLINE | ID: mdl-38836736

ABSTRACT

Objective: This study aimed to investigate the efficacy of electroacupuncture (EA) combined with growth hormone in alleviating quadriceps atrophy and enhancing knee function following quadriceps ligament reconstruction. Methods: A prospective study was conducted, and a total of 90 patients exhibiting quadriceps atrophy after anterior cruciate ligament reconstruction were recruited between July 2020 and July 2022 from Shenzhen Pingle Orthopedic Hospital. They were randomly assigned to either the control group or the observation group , with 45 patients in each. The control group received routine rehabilitation training along with growth hormone treatment, while the observation group received routine rehabilitation training in addition to EA and growth hormone treatment. The study assessed the visual analogue score (VAS) for postoperative pain, knee function, and clinical outcomes in both groups. Results: The total effective rate in the observation group was significantly higher compared to the control group, with a statistically significant difference (P < .05). Initially, there were no significant differences between the two groups in peri-thigh atrophy index, VAS score, Lysholm score, knee swelling, knee stability, and range of motion (ROM) score (P > .05). However, after 3 and 6 months of treatment, significant reductions were observed in peri-thigh atrophy index, VAS score, knee swelling, and ROM score in the observation group compared to the control group (P < .05). Moreover, Lysholm score and knee stability significantly increased in the observation group (P < .05), with changes significantly higher than those in the control group (P < .05). Conclusions: EA combined with growth hormone treatment significantly reduces quadriceps atrophy and knee joint function in patients undergoing anterior cruciate ligament reconstruction. This combination therapy holds promise for enhancing rehabilitation outcomes in this patient population.

3.
Eur J Med Res ; 29(1): 310, 2024 Jun 06.
Article in English | MEDLINE | ID: mdl-38840262

ABSTRACT

KDM6A (lysine demethylase 6A) has been reported to undergo inactivating mutations in colorectal cancer, but its function in the progression of colorectal cancer has not been evaluated using animal models of colorectal cancer. In this study, we found that knocking out KDM6A expression in mouse intestinal epithelium increased the length of villus and crypt, promoting the development of AOM (azoxymethane)/DSS (dextran sulfate sodium salt)-induced colorectal cancer. On the other hand, knocking down KDM6A expression promoted the growth of colorectal cancer cells. In molecular mechanism studies, we found that KDM6A interacts with HIF-1α; knocking down KDM6A promotes the binding of HIF-1α to the LDHA promoter, thereby promoting LDHA expression and lactate production, enhancing glycolysis. Knocking down LDHA reversed the malignant phenotype caused by KDM6A expression loss. In summary, this study using animal models revealed that KDM6A loss promotes the progression of colorectal cancer through reprogramming the metabolism of the colorectal cancer cells, suggesting that restoring the function of KDM6A is likely to be one of the strategies for colorectal cancer treatment.


Subject(s)
Colorectal Neoplasms , Disease Progression , Glycolysis , Histone Demethylases , Animals , Humans , Mice , Cell Proliferation/genetics , Colorectal Neoplasms/pathology , Colorectal Neoplasms/genetics , Colorectal Neoplasms/metabolism , Gene Expression Regulation, Neoplastic , Histone Demethylases/metabolism , Histone Demethylases/genetics , Hypoxia-Inducible Factor 1, alpha Subunit/metabolism , Hypoxia-Inducible Factor 1, alpha Subunit/genetics
4.
Alpha Psychiatry ; 25(1): 23-29, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38799488

ABSTRACT

Objective: Schizophrenia patients often have personality disorders; schizophrenia patients with personality disorders are more difficult to treat and have a worse prognosis. Early identification of this group of patients and early intervention can achieve better prognosis. Therefore, it is very important to explore effective biomarkers and early diagnosis for the prognosis of schizophrenia. The primary purpose of this paper is to explore the relationship between plasma miRNA expression level and personality disorder with schizophrenia. Methods: Gene microarrays in miRNA files were employed, and the plasma of peripheral blood of 82 schizophrenic patients and 43 healthy control subjects were examined. Real-time reverse transcription polymerase chain reaction detection were performed to explore the results. Spearman correlation analysis was used to analyze the correlation between expression level of miRNAs and Personality Diagnosis Questionnaire-4 score. Results: The results showed that miR-1273d, miR-1303, miR-3064-5p, miR-3131, miR-3687, miR-4428, miR-4725-3p, and miR-5096 were up-regulated in schizophrenic patients. Compared to healthy control subjects, the difference was statistically significant (P < .05). Schizophrenic patients with schizoid, paranoid, schizotypal, and obsessive compulsive traits had negative correlation with miR-1303, miR-3131, miR-4428, and miR-5096 expression level (r = -0.40 to -0.62, P < .05); there were no significant differences in the other miRNAs. Correlation with other personality traits was not significant (P > .05). The stepwise regression analysis indicated that miR-5096, miR-3131, and miR-1273d have a significant predictive effect on the schizoid trait (P < .01). MiR-4428 and miR-1303 had a significant predictive effect on the schizotypal trait (P < .01). MiR-5096, miR-4428, and miR-4725-3P had a significant predictive effect on the paranoid trait (P < .05). MiR-4428, miR-1303, and miR-5096 had a significant predictive effect on the obsessive compulsive trait (P < .05). Conclusion: The expression levels of miR-1273d, miR-1303, miR-3064-5p, miR-3131, miR-3687, miR-4428, miR-4725-3p, and miR-5096 were up-regulated in the peripheral blood of patients with schizophrenia, and these miRNAs are expected to be diagnostic biomarkers for accurate diagnosis of schizophrenia. The expression levels of miR-1303, miR-3131, miR-1273d, miR-4428, miR-4725-3p, and miR-5096 have significant predictive effects on personality disorder in schizophrenia.

5.
Nano Lett ; 24(20): 6183-6191, 2024 May 22.
Article in English | MEDLINE | ID: mdl-38728596

ABSTRACT

Two-dimensional (2D) materials are promising candidates for spintronic applications. Maintaining their atomically smooth interfaces during integration of ferromagnetic (FM) electrodes is crucial since conventional metal deposition tends to induce defects at the interfaces. Meanwhile, the difficulties in picking up FM metals with strong adhesion and in achieving conductance match between FM electrodes and spin transport channels make it challenging to fabricate high-quality 2D spintronic devices using metal transfer techniques. Here, we report a solvent-free magnetic electrode transfer technique that employs a graphene layer to assist in the transfer of FM metals. It also serves as part of the FM electrode after transfer for optimizing spin injection, which enables the realization of spin valves with excellent performance based on various 2D materials. In addition to two-terminal devices, we demonstrate that the technique is applicable for four-terminal spin valves with nonlocal geometry. Our results provide a promising future of realizing 2D spintronic applications using the developed magnetic electrode transfer technique.

6.
Front Cell Neurosci ; 18: 1339345, 2024.
Article in English | MEDLINE | ID: mdl-38638299

ABSTRACT

Introduction: Protocadherin-19 (PCDH19)-Clustering Epilepsy (PCE) is a developmental and epileptic encephalopathy caused by loss-of-function variants of the PCDH19 gene on the X-chromosome. PCE affects females and mosaic males while male carriers are largely spared. Mosaic expression of the cell adhesion molecule PCDH19 due to random X-chromosome inactivation is thought to impair cell-cell interactions between mutant and wild type PCDH19-expressing cells to produce the disease. Progress has been made in understanding PCE using rodent models or patient induced pluripotent stem cells (iPSCs). However, rodents do not faithfully model key aspects of human brain development, and patient iPSC models are limited by issues with random X-chromosome inactivation. Methods: To overcome these challenges and model mosaic PCDH19 expression in vitro, we generated isogenic female human embryonic stem cells with either HA-FLAG-tagged PCDH19 (WT) or homozygous PCDH19 knockout (KO) using genome editing. We then mixed GFP-labeled WT and RFP-labeled KO cells and generated human cortical organoids (hCOs). Results: We found that PCDH19 is highly expressed in early (days 20-35) WT neural rosettes where it co-localizes with N-Cadherin in ventricular zone (VZ)-like regions. Mosaic PCE hCOs displayed abnormal cell sorting in the VZ with KO and WT cells completely segregated. This segregation remained robust when WT:KO cells were mixed at 2:1 or 1:2 ratios. PCE hCOs also exhibited altered expression of PCDH19 (in WT cells) and N-Cadherin, and abnormal deep layer neurogenesis. None of these abnormalities were observed in hCOs generated by mixing only WT or only KO (modeling male carrier) cells. Discussion: Our results using the mosaic PCE hCO model suggest that PCDH19 plays a critical role in human VZ radial glial organization and early cortical development. This model should offer a key platform for exploring mechanisms underlying PCE-related cortical hyperexcitability and testing of potential precision therapies.

7.
Talanta ; 274: 126004, 2024 Jul 01.
Article in English | MEDLINE | ID: mdl-38564824

ABSTRACT

Reactive oxygen species (ROS), reactive nitrogen species (RNS), and reactive sulfur species (RSS) serve as vital mediators essential for preserving intracellular redox homeostasis within the human body, thereby possessing significant implications across physiological and pathological domains. Nevertheless, deviations from normal levels of ROS, RNS, and RSS disturb redox homeostasis, leading to detrimental consequences that compromise bodily integrity. This disruption is closely linked to the onset of various human diseases, thereby posing a substantial threat to human health and survival. Small-molecule fluorescent probes exhibit considerable potential as analytical instruments for the monitoring of ROS, RNS, and RSS due to their exceptional sensitivity and selectivity, operational simplicity, non-invasiveness, localization capabilities, and ability to facilitate in situ optical signal generation for real-time dynamic analyte monitoring. Due to their distinctive transition from their spirocyclic form (non-fluorescent) to their ring-opened form (fluorescent), along with their exceptional light stability, broad wavelength range, high fluorescence quantum yield, and high extinction coefficient, rhodamine fluorophores have been extensively employed in the development of fluorescent probes. This review primarily concentrates on the investigation of fluorescent probes utilizing rhodamine dyes for ROS, RNS, and RSS detection from the perspective of different response groups since 2016. The scope of this review encompasses the design of probe structures, elucidation of response mechanisms, and exploration of biological applications.


Subject(s)
Fluorescent Dyes , Reactive Nitrogen Species , Reactive Oxygen Species , Rhodamines , Fluorescent Dyes/chemistry , Rhodamines/chemistry , Reactive Nitrogen Species/analysis , Humans , Reactive Oxygen Species/metabolism , Reactive Oxygen Species/analysis , Optical Imaging , Animals , Sulfur/chemistry , Sulfur/analysis
8.
Opt Express ; 32(7): 11801-11817, 2024 Mar 25.
Article in English | MEDLINE | ID: mdl-38571019

ABSTRACT

A full-quantum approach is used to study the quantum nonlinear properties of a compound Michelson-Sagnac interferometer optomechanical system. By deriving the effective Hamiltonian, we find that the reduced system exhibits a Kerr nonlinear term with a complex coefficient, entirely induced by the dissipative and dispersive couplings. Unexpectedly, the nonlinearities resulting from the dissipative coupling possess non-Hermitian Hamiltonian-like properties preserving the quantum nature of the dispersive coupling beyond the traditional system dissipation. This protective mechanism allows the system to exhibit strong quantum nonlinear effects when the detuning (the compound cavity detuning Δc and the auxiliary cavity detuning Δe) and the tunneling coupling strength (J) of two cavities satisfy the relation J2 = ΔcΔe. Moreover, the additive effects of dispersive and dissipative couplings can produce strong anti-bunching effects, which exist in both strong and weak coupling conditions. Our work may provide a new way to study and produce strong quantum nonlinear effects in dissipatively coupled optomechanical systems.

9.
Nat Commun ; 15(1): 2992, 2024 Apr 06.
Article in English | MEDLINE | ID: mdl-38582768

ABSTRACT

Nonlinear transport is a unique functionality of noncentrosymmetric systems, which reflects profound physics, such as spin-orbit interaction, superconductivity and band geometry. However, it remains highly challenging to enhance the nonreciprocal transport for promising rectification devices. Here, we observe a light-induced giant enhancement of nonreciprocal transport at the superconducting and epitaxial CaZrO3/KTaO3 (111) interfaces. The nonreciprocal transport coefficient undergoes a giant increase with three orders of magnitude up to 105 A-1 T-1. Furthermore, a strong Rashba spin-orbit coupling effective field of 14.7 T is achieved with abundant high-mobility photocarriers under ultraviolet illumination, which accounts for the giant enhancement of nonreciprocal transport coefficient. Our first-principles calculations further disclose the stronger Rashba spin-orbit coupling strength and the longer relaxation time in the photocarrier excitation process, bridging the light-property quantitative relationship. Our work provides an alternative pathway to boost nonreciprocal transport in noncentrosymmetric systems and facilitates the promising applications in opto-rectification devices and spin-orbitronic devices.

10.
J Comput Chem ; 45(20): 1737-1743, 2024 Jul 30.
Article in English | MEDLINE | ID: mdl-38622788

ABSTRACT

We present a comprehensive investigation of the electronic properties of fluorinated monolayer violet phosphorus using first-principles calculations. Our results reveal a strong dependence of the electronic properties on the different fluorine coverages of fluorination. As the fluorine coverage increases, monolayer violet phosphorus undergoes a significant transition from a wide direct bandgap semiconductor to a narrow indirect bandgap semiconductor. Moreover, both semi-fluorinated and fully fluorinated monolayer violet phosphorus exhibit advantageous semiconducting characteristics, with a tunable bandgap of 0.50 ~ 1.04 eV under biaxial strain ranging from -6% to 6%. Notably, the fully fluorinated monolayer violet phosphorus demonstrates a higher coefficient of light absorption within the visible range. Therefore, our findings highlight the tunability of monolayer violet phosphorus properties through the absorption of various fluorine coverages, providing valuable insights for the design and development of novel semiconductor devices based on this material.

11.
Methods Mol Biol ; 2760: 209-217, 2024.
Article in English | MEDLINE | ID: mdl-38468091

ABSTRACT

Emerging microorganism Pseudomonas putida KT2440 is utilized for the synthesis of biobased chemicals from renewable feedstocks and for bioremediation. However, the methods for analyzing, engineering, and regulating the biosynthetic enzymes and protein complexes in this organism remain underdeveloped.Such attempts can be advanced by the genetic code expansion-enabled incorporation of noncanonical amino acids (ncAAs) into proteins, which also enables further controls over the strain's biological processes. Here, we give a step-by-step account of the incorporation of two ncAAs into any protein of interest (POI) in response to a UAG stop codon by two commonly used orthogonal archaeal tRNA synthetase and tRNA pairs. Using superfolder green fluorescent protein (sfGFP) as an example, this method lays down a solid foundation for future work to study and enhance the biological functions of KT2440.


Subject(s)
Amino Acyl-tRNA Synthetases , Pseudomonas putida , Pseudomonas putida/genetics , Pseudomonas putida/metabolism , Genetic Code , Amino Acids/genetics , Amino Acids/metabolism , RNA, Transfer/genetics , RNA, Transfer/metabolism , Amino Acyl-tRNA Synthetases/metabolism
12.
Article in English | MEDLINE | ID: mdl-38514038

ABSTRACT

Multiple lines of evidence suggest that the trace amine-associated receptor 1 (TAAR1) holds promise as a potential target for stress-related disorders, such as treating major depressive disorder (MDD). The role of TAAR1 in the regulation of adult neurogenesis is recently supported by transcriptomic data. However, it remains unknown whether TAAR1 in dentate gyrus (DG) mediate chronic stress-induced negative effects on hippocampal plasticity and related behavior in mice. The present study consisted of a series of experiments using RNAscope, genetic approaches, behavioral tests, immunohistochemical staining, Golgi-Cox technique to unravel the effects of TAAR1 on alterations of dentate neuronal plasticity and cognitive function in the chronic social defeat stress model. The mice subjected to chronic defeat stress exhibited a noteworthy decrease in the mRNA level of TAAR1 in DG. Additionally, they exhibited compromised social memory and spatial object recognition memory, as well as impaired proliferation and maturation of adult-born dentate granule cells. Moreover, the selective knockout TAAR1 in DG mostly mimicked the cognitive function deficits and neurogenesis impairment induced by chronic stress. Importantly, the administration of the selective TAAR1 partial agonist RO5263397 during stress exposure attenuated the adverse effects of chronic stress on cognitive function, adult neurogenesis, dendritic arborization, and the synapse number of dentate neurons in DG. In summary, our findings suggest that TAAR1 plays a crucial role in mediating the detrimental effects of chronic stress on hippocampal plasticity and cognition. TAAR1 agonists exhibit therapeutic potential for individuals suffering from cognitive impairments associated with MDD.


Subject(s)
Dentate Gyrus , Depressive Disorder, Major , Receptors, G-Protein-Coupled , Animals , Mice , Dentate Gyrus/physiology , Hippocampus/physiology , Cognition/physiology , Neuronal Plasticity/physiology , Neurogenesis
13.
Nat Commun ; 15(1): 2605, 2024 Mar 23.
Article in English | MEDLINE | ID: mdl-38521797

ABSTRACT

Nonlinear transport enabled by symmetry breaking in quantum materials has aroused considerable interest in condensed matter physics and interdisciplinary electronics. However, achieving a nonlinear optical response in centrosymmetric Dirac semimetals via defect engineering has remained a challenge. Here, we observe the helicity dependent terahertz emission in Dirac semimetal PtTe2 thin films via the circular photogalvanic effect under normal incidence. This is activated by a controllable out-of-plane Te-vacancy defect gradient, which we unambiguously evidence with electron ptychography. The defect gradient lowers the symmetry, which not only induces the band spin splitting but also generates the giant Berry curvature dipole responsible for the circular photogalvanic effect. We demonstrate that the THz emission can be manipulated by the Te-vacancy defect concentration. Furthermore, the temperature evolution of the THz emission features a minimum in the THz amplitude due to carrier compensation. Our work provides a universal strategy for symmetry breaking in centrosymmetric Dirac materials for efficient nonlinear transport.

14.
J Biotechnol ; 385: 1-12, 2024 Apr 10.
Article in English | MEDLINE | ID: mdl-38428504

ABSTRACT

Emerging consumer demand for safer, more sustainable flavors and fragrances has created new challenges for the industry. Enzymatic syntheses represent a promising green production route, but the broad application requires engineering advancements for expanded diversity, improved selectivity, and enhanced stability to be cost-competitive with current methods. This review discusses recent advances and future outlooks for enzyme engineering in this field. We focus on carboxylic acid reductases (CARs) and unspecific peroxygenases (UPOs) that enable selective productions of complex flavor and fragrance molecules. Both enzyme types consist of natural variants with attractive characteristics for biocatalytic applications. Applying protein engineering methods, including rational design and directed evolution in concert with computational modeling, present excellent examples for property improvements to unleash the full potential of enzymes in the biosynthesis of value-added chemicals.


Subject(s)
Odorants , Oxidoreductases , Oxidoreductases/metabolism , Mixed Function Oxygenases/metabolism
15.
Adv Mater ; 36(24): e2311591, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38426690

ABSTRACT

2D van der Waals (vdW) magnets open landmark horizons in the development of innovative spintronic device architectures. However, their fabrication with large scale poses challenges due to high synthesis temperatures (>500 °C) and difficulties in integrating them with standard complementary metal-oxide semiconductor (CMOS) technology on amorphous substrates such as silicon oxide (SiO2) and silicon nitride (SiNx). Here, a seeded growth technique for crystallizing CrTe2 films on amorphous SiNx/Si and SiO2/Si substrates with a low thermal budget is presented. This fabrication process optimizes large-scale, granular atomic layers on amorphous substrates, yielding a substantial coercivity of 11.5 kilo-oersted, attributed to weak intergranular exchange coupling. Field-driven Néel-type stripe domain dynamics explain the amplified coercivity. Moreover, the granular CrTe2 devices on Si wafers display significantly enhanced magnetoresistance, more than doubling that of single-crystalline counterparts. Current-assisted magnetization switching, enabled by a substantial spin-orbit torque with a large spin Hall angle (85) and spin Hall conductivity (1.02 × 107 ℏ/2e Ω⁻¹ m⁻¹), is also demonstrated. These observations underscore the proficiency in manipulating crystallinity within integrated 2D magnetic films on Si wafers, paving the way for large-scale batch manufacturing of practical magnetoelectronic and spintronic devices, heralding a new era of technological innovation.

16.
J Cutan Pathol ; 51(7): 530-537, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38549184

ABSTRACT

BACKGROUND: Dermatopathology education accounts for 30% of U.S. dermatology residency training. The COVID-19 pandemic expedited the implementation of virtual dermatopathology in place of traditional microscopy for resident education. This study examined U.S. dermatology residents' perceptions of virtual dermatopathology, as research in this area is lacking. METHODS: An anonymous, confidential, institutional review board-approved survey was electronically distributed to U.S. dermatology residents consisting of 16 questions comparing attitudes towards virtual and traditional dermatopathology education. Responses were n = 59. Statistical analysis was performed using SAS software. RESULTS: Participants believe virtual imaging is superior to conventional microscopy in schedule flexibility (96.6% vs. 1.7%, p < 0.0001), lecture convenience (94.8% vs. 0.0%, p < 0.0001), personal review (96.6% vs. 0.0%, p < 0.0001), cost-effectiveness (64.4% vs. 6.8%, p < 0.0001), and board exam preparation (52.5% vs. 16.9%, p = 0.0005). Conventional microscopy was favored for image quality (50.8% vs. 25.4%, p = 0.0127) and overall utility (50.8% vs. 27.1%, p = 0.0195). CONCLUSIONS: Our study supports virtual dermatopathology utilization as a valuable tool in dermatology residency training. Also it is shown that conventional microscopy training continues to play a key role. Further studies should examine whether, if ever, virtual dermatopathology could gradually replace conventional microscopy with the advent of newer and more powerful digital and scanning technology.


Subject(s)
COVID-19 , Dermatology , Internship and Residency , Dermatology/education , Humans , Internship and Residency/methods , Surveys and Questionnaires , United States , SARS-CoV-2 , Male , Attitude of Health Personnel , Female , Microscopy/methods
17.
Adv Sci (Weinh) ; 11(17): e2307034, 2024 May.
Article in English | MEDLINE | ID: mdl-38353386

ABSTRACT

Exchange bias is extensively studied and widely utilized in spintronic devices, such as spin valves and magnetic tunnel junctions. 2D van der Waals (vdW) magnets, with high-quality interfaces in heterostructures, provide an excellent platform for investigating the exchange bias effect. To date, intrinsic modulation of exchange bias, for instance, via precise manipulation of the magnetic phases of the antiferromagnetic layer, is yet to be fully reached, owing partly to the large exchange fields of traditional bulk antiferromagnets. Herein, motivated by the low-field spin-flop transition of a 2D antiferromagnet, CrPS4, exchange bias is explored by modulating the antiferromagnetic spin-flop phase transition in all-vdW magnetic heterostructures. The results demonstrate that undergoing the spin-flop transition during the field cooling process, the A-type antiferromagnetic ground state of CrPS4 turns into a canted antiferromagnetic one, therefore, it reduces the interfacial magnetic coupling and suppresses the exchange bias. Via conducting different cooling fields, one can select the exchange bias effect switching among the "ON", "depressed", and "OFF" states determined by the spin flop of CrPS4. This work provides an approach to intrinsically modulate the exchange bias in all-vdW heterostructures and paves new avenues to design and manipulate 2D spintronic devices.

18.
Int Immunopharmacol ; 127: 111322, 2024 Jan 25.
Article in English | MEDLINE | ID: mdl-38064814

ABSTRACT

AIM OF THE STUDY: This study aims to reveal the role of Tanshinone I (TI) in inhibiting osteoclast activity and bone loss in vitro and in vivo, as well as elucidate its underlying molecular mechanism. MATERIALS AND METHODS: A mouse model of estrogen deficiency was used to assess the inhibitory effect of TI on osteoclast activity and subsequent bone loss. To validate the impact of TI on osteoclast formation, TRAcP staining and pseudopodia belt staining were conducted. The expressions of osteoclast-specific genes and proteins were evaluated using RT-PCR and Western Blot analyses. Additionally, immunofluorescence staining was employed to examine the effect of TI on p65 nuclear translocation and the expression level of reactive oxygen species (ROS). RESULTS: TI demonstrated significant efficacy in alleviating bone mass loss and suppressing osteoclast activity and function in ovariectomized mice. This outcome was predominantly ascribed to a decrease in ROS levels, thereby impeding the NF-κB signaling pathway and the translocation of p65 to the nucleus. Additionally, TI hindered the RANKL-induced phosphorylation of the MAPK signaling pathway. Moreover, TI played a role in the reduction of osteoclast-specific genes and proteins. CONCLUSIONS: To summarize, this study sheds light on TI's capacity to modulate various signaling pathways triggered by RANKL, effectively impeding osteoclast formation and mitigating bone loss resulting from estrogen deficiency. Consequently, TI emerges as a promising therapeutic option for estrogen-deficiency bone loss.


Subject(s)
Abietanes , Bone Diseases, Metabolic , Bone Resorption , Mice , Animals , NF-kappa B/metabolism , Osteogenesis , Reactive Oxygen Species/metabolism , Signal Transduction , Osteoclasts , Estrogens/pharmacology , Estrogens/therapeutic use , Estrogens/metabolism , RANK Ligand/metabolism , Bone Resorption/drug therapy , Bone Resorption/metabolism , Cell Differentiation
19.
Arch Orthop Trauma Surg ; 144(2): 651-662, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38006437

ABSTRACT

INTRODUCTION: After locking plate (LP) fixation, secondary screw perforation (SSP) is the most common complication in proximal humerus fracture (PHF). SSP is the main cause of glenoid destruction and always leads to reoperation. This study aimed to identify independent risk parameters for SSP and establish an individualized risk prognostic model to facilitate its clinical management. METHODS: We retrospectively reviewed the medical information of patients with PHF who underwent open reduction and internal LP fixation at one medical center (n = 289) between June 2013 and June 2021. Uni- and multivariate regression analyses identified the independent risk factors. A novel nomogram was formulated based on the final independent risk factors for predicting the risk of SSP. We performed internal validation through concordance indices (C-index) and calibration curves. To implement the clinical use of the model, we performed decision curve analyses (DCA) and risk stratification according to the optimal cutoff value. RESULTS: A total of 232 patients who met the inclusion criteria were enrolled. The incidence of SSP was 21.98% at the last follow-up. We found that fracture type (odds ratio [OR], 3.111; 95% confidence interval [CI], 1.223-7.914; P = 0.017), postoperative neck-shaft angle (OR, 4.270; 95% CI 1.622-11.239; P = 0.003), the absence of calcar screws (OR, 3.962; 95% CI 1.753-8.955; P = 0.003), and non-medial metaphyseal support (OR,7.066; 95% CI 2.747-18.174; P = 0.000) were independent predictors of SSP. Based on these variables, we developed a nomogram that showed good discrimination (C-index = 0.815). The predicted values of the new model were in good agreement with the actual values demonstrated by the calibration curve. Furthermore, the model's DCA and risk stratification (cutoff = 140 points) showed significantly higher clinical benefits. CONCLUSIONS: We developed and validated a visual and personalized nomogram that could predict the individual risk of SSP and provide a decision basis for surgeons to create the most optional management plan. However, future prospective and externally validated design studies are warranted to verify our model's efficacy.


Subject(s)
Humeral Fractures , Shoulder Fractures , Humans , Prognosis , Retrospective Studies , Bone Screws , Fracture Fixation, Internal/adverse effects , Shoulder Fractures/surgery , Bone Plates , Risk Assessment , Humerus/surgery , Treatment Outcome
20.
Eur J Med Chem ; 264: 115976, 2024 Jan 15.
Article in English | MEDLINE | ID: mdl-38039794

ABSTRACT

A series of novel benzothiozinone (BTZ) derivatives were designed, prepared and evaluated for antituberculosis activity. Specifically, the BTZ pharmacophore is retained and the previous heterocyclic ring linker is replaced by alkynyl or vinyl linker, the resulting compounds displayed about 5-fold improved antimycobacterial activity. We further revealed that the linker attached tail group affects the compound metabolic stability, potency and other drug like properties. This work led to the discovery of two compounds (A1 and A11) with acceptable low MICs and improved metabolic stability. The representative compound A11 demonstrated bactericidal efficacy in an acute TB infection mouse model.


Subject(s)
Antitubercular Agents , Mycobacterium tuberculosis , Mice , Animals , Antitubercular Agents/chemistry , Structure-Activity Relationship , Microbial Sensitivity Tests
SELECTION OF CITATIONS
SEARCH DETAIL
...