Large Field-like Spin-Orbit Torque and Enhanced Magnetization Switching Efficiency Utilizing Amorphous Mo.

Spin-orbit torque magnetic random access memory (SOT-MRAM) has great promise in high write speed and low power consumption. Mo can play a vital role in constructing a CoFeB/MgO-based MRAM cell because of its ability to enhance the perpendicular magnetic anisotropy (PMA), thermal tolerance, and tunneling magnetoresistance. However, Mo is often considered as a less favorable candidate among SOT materials because of its weak spin-orbit coupling. In this study, we experimentally investigate the SOT efficiencies in Mo/CoFeB/MgO heterostructures over a wide range of Mo thicknesses and temperature. Decent damping-like SOT efficiency |ξDL| = 0.015 ± 0.001 and field-like SOT efficiency |ξFL| = 0.050 ± 0.001 are found in amorphous Mo. The ξFL/ξDL ratio is greater than 3. Furthermore, efficient current-induced magnetization switching is demonstrated with the critical current density comparable with heavy metal Ir and W. Our work reveals new understanding and possibilities for Mo as both an SOT source component and PMA buffer layer in the implementation of SOT-MRAMs.

A novel method for synthesizing authentic SARS-CoV-2 main protease.

The SARS-CoV-2 main protease (Mpro) plays a crucial role in virus amplification and is an ideal target for antiviral drugs. Currently, authentic Mpro is prepared through two rounds of proteolytic cleavage. In this method, Mpro carries a self-cleavage site at the N-terminus and a protease cleavage site followed by an affinity tag at the C-terminus. This article proposes a novel method for producing authentic Mpro through single digestion. Mpro was constructed by fusing a His tag containing TEV protease cleavage sites at the N-terminus. The expressed recombinant protein was digested by TEV protease, and the generated protein had a decreased molecular weight and significantly increased activity, which was consistent with that of authentic Mpro generated by the previous method. These findings indicated that authentic Mpro was successfully obtained. Moreover, the substrate specificity of Mpro was investigated. Mpro had a strong preference for Phe at position the P2, which suggested that the S2 subsite was an outstanding target for designing inhibitors. This article also provides a reference for the preparation of Mpro for sudden coronavirus infection in the future.

Attachment and Clinical Outcomes Among Treatment-Seeking Adults With Persistent Symptoms After Mild Traumatic Brain Injury.

OBJECTIVE: Interpersonal attachment influences the development and course of disease. Overreliance on insecure attachment strategies may increase risk for poor disease outcomes. This study aimed to investigate largely unexplored relationships between attachment strategies and clinical outcomes among adults with persistent symptoms after mild traumatic brain injury (mTBI). METHODS: Participants with persistent symptoms after mTBI (N=83) completed measures assessing dimensions of insecure attachment (Relationship Scales Questionnaire [RSQ]), persistent symptoms (Rivermead Post-Concussion Symptoms Questionnaire), depression (Patient Health Questionnaire-9), anxiety (Generalized Anxiety Disorder-7), and health-related quality of life (HRQOL) (Quality of Life After Brain Injury-Overall Scale). Questionnaires were administered at clinic intake (mean=18.1 weeks postinjury) and again 3-4 months later (mean=32.2 weeks postinjury), except the RSQ, which was administered only in the follow-up assessment. Treatment response for each outcome was calculated as the difference between scores at clinic intake and follow-up. Generalized linear models were fitted for each clinical outcome, with RSQ variables as predictors. RESULTS: Higher attachment anxiety was associated with greater persistent symptom severity, greater depression and anxiety symptoms, and worse HRQOL at follow-up. Higher attachment anxiety was also associated with less improvement in depression and HRQOL over time. In contrast, attachment avoidance was unrelated to any of the clinical outcomes. CONCLUSIONS: Attachment anxiety, the fear that a significant other will not be available in stressful circumstances, may be a particularly important social factor associated with health among adults with persistent symptoms after mTBI. Greater consideration of the attachment system is warranted in mTBI care and research.

Observation of the antiferromagnetic spin Hall effect.

The discovery of the spin Hall effect1 enabled the efficient generation and manipulation of the spin current. More recently, the magnetic spin Hall effect2,3 was observed in non-collinear antiferromagnets, where the spin conservation is broken due to the non-collinear spin configuration. This provides a unique opportunity to control the spin current and relevant device performance with controllable magnetization. Here, we report a magnetic spin Hall effect in a collinear antiferromagnet, Mn2Au. The spin currents are generated at two spin sublattices with broken spatial symmetry, and the antiparallel antiferromagnetic moments play an important role. Therefore, we term this effect the 'antiferromagnetic spin Hall effect'. The out-of-plane spins from the antiferromagnetic spin Hall effect are favourable for the efficient switching of perpendicular magnetized devices, which is required for high-density applications. The antiferromagnetic spin Hall effect adds another twist to the atomic-level control of spin currents via the antiferromagnetic spin structure.

A water-soluble polysaccharide from Eucommia folium: the structural characterization and anti-tumor activity in vivo.

In this study, a water-soluble polysaccharide from Eucommia folium was extracted by hot water and purified using Sephadex G-200 gel columns. The results showed that the purified fraction (EFP) has a molecular weight of 9.98 × 105 Da and consisted of rhamnose, arabinose, galactose, glucose, mannose, xylose, galacturonic acid, and glucuronic acid (molar ratio: 0.226: 1.739: 2.183: 1: 0.155: 0.321: 0.358: 0.047). The combination of infrared spectroscopy and NMR analysis proved that EFP is an acidic polysaccharide whose main chain consists of α-L-Araf-(1 → , → 3,5)-α-Araf-(1 → , → 3)-ß-Galp-(1 → , → 3,6)-ß-Glcp-(1 → , → 2)-α-D-Manp-(1 → , → 4)-α-GalpA-(1 → , → 2,4)-α-Rhap-(1 → . In addition, the in vivo antitumoral activity of EFP was studied using a H22 tumor-bearing mice model. EFP effectively inhibited tumor growth in mice following intragastric administration. By Combining with the results of the apoptosis assay and JC-1 staining analysis, we confirmed that EFP induces apoptosis through the mitochondrial pathway. Furthermore, cell cycle analysis demonstrated that EFP blocks the cell cycle at S phase.

Multi-method study of the implementation of Cognitive Symptom Management and Rehabilitation Training (CogSMART) in real-world settings.

Cognitive Symptom Management and Rehabilitation Training (CogSMART) and Compensatory Cognitive Training (CCT) are evidence-based compensatory cognitive training interventions that improve cognition in persons with a history of traumatic brain injury or other neuropsychiatric disorders. Despite demonstrated efficacy, use and effectiveness of CogSMART/CCT in real-world settings is not known.We used a multi-method design to collect and analyze quantitative and qualitative survey data from several domains of the Reach, Effectiveness, Adoption, Implementation, and Maintenance (RE-AIM) framework to gather information about use of CogSMART/CCT in real-world settings from provider and patient perspectives. Surveys were sent to email addresses from persons who registered on the CogSMART website seeking access to training manuals and other resources. Descriptive statistics were generated, and we used Natural Language Processing methods to study the self-report free responses. Using n-gram analysis, we identified the most frequently reported responses.We found CogSMART/CCT was broadly used in real-world settings and delivered by a variety of providers for several patient groups with high attendance and overall high satisfaction. CogSMART/CCT seemed to be offered in VA- or university-related clinics more than in private practice or rehabilitation centers. The diversity of providers and variety of formats by which to deliver CogSMART/CCT (i.e., individual, group, telehealth) seemed to play a role in its widespread implementation, as did its adaptability. Most providers made adaptations to the intervention that reduced the length or number of sessions. These changes were most likely to be based on client characteristics. The low rates of formal training, however, may have contributed to lower levels of perceived helpfulness among patients.Reach and Adoption of a cognitive rehabilitation intervention improved by increasing access to the manuals. Attention to characteristics of dissemination and implementation in the design of an intervention may enhance its use in real-world settings. The relevant outcomes, easy access to training manuals, and adaptability of CogSMART/CCT seem to have been important factors in its use in a variety of settings and for several disorders with cognitive impairment. The adoption of CogSMART/CCT by a variety of providers other than neuropsychologists suggests its use may be broadened to other healthcare providers, if adequately trained, to increase access to an intervention with demonstrated efficacy for cognitive rehabilitation for several neuropsychiatric disorders.

Long spin coherence length and bulk-like spin-orbit torque in ferrimagnetic multilayers.

Spintronics relies on magnetization switching through current-induced spin torques. However, because spin transfer torque for ferromagnets is a surface torque, a large switching current is required for a thick, thermally stable ferromagnetic cell, and this remains a fundamental obstacle for high-density non-volatile applications with ferromagnets. Here, we report a long spin coherence length and associated bulk-like torque characteristics in an antiferromagnetically coupled ferrimagnetic multilayer. We find that a transverse spin current can pass through >10-nm-thick ferrimagnetic Co/Tb multilayers, whereas it is entirely absorbed by a 1-nm-thick ferromagnetic Co/Ni multilayer. We also find that the switching efficiency of Co/Tb multilayers partially reflects a bulk-like torque characteristic, as it increases with ferrimagnet thickness up to 8 nm and then decreases, in clear contrast to the 1/thickness dependence of ferromagnetic Co/Ni multilayers. Our results on antiferromagnetically coupled systems will invigorate research towards the development of energy-efficient spintronics.

Nonlinear Planar Hall Effect.

An intriguing property of a three-dimensional (3D) topological insulator (TI) is the existence of surface states with spin-momentum locking, which offers a new frontier of exploration in spintronics. Here, we report the observation of a new type of Hall effect in a 3D TI Bi_{2}Se_{3} film. The Hall resistance scales linearly with both the applied electric and magnetic fields and exhibits a π/2 angle offset with respect to its longitudinal counterpart, in contrast to the usual angle offset of π/4 between the linear planar Hall effect and the anisotropic magnetoresistance. This novel nonlinear planar Hall effect originates from the conversion of a nonlinear transverse spin current to a charge current due to the concerted actions of spin-momentum locking and time-reversal symmetry breaking, which also exists in a wide class of noncentrosymmetric materials with a large span of magnitude. It provides a new way to characterize and utilize the nonlinear spin-to-charge conversion in a variety of topological quantum materials.

Catastrophizing is associated with excess cognitive symptom reporting after mild traumatic brain injury.

OBJECTIVE: Persistent cognitive symptoms after mild traumatic brain injury (mTBI) often do not correlate with objective neuropsychological performance. Catastrophizing (i.e., excessively negative interpretations of symptoms) may help explain this discrepancy. We hypothesize that symptom catastrophizing will be associated with greater cognitive symptom reporting relative to neuropsychological test performance in people seeking treatment for mTBI. METHOD: Secondary analysis of baseline data from a randomized controlled trial. Adults with mTBI (N = 77) were recruited from two outpatient mTBI clinics in British Columbia, Canada. Questionnaires and assessments were administered at baseline (M = 17.7 weeks postinjury). The sample was 64% women with a mean age of 42 years (SD = 11.5). Validated questionnaires were used to assess catastrophizing, cognitive symptoms, and affective distress. Neuropsychological performance was assessed using the National Institutes of Health Toolbox Cognition Battery. Discrepancies between cognitive symptoms and cognitive functioning were operationalized using standard residuals from neuropsychological test performance scores regressed on cognitive symptom scores. Generalized linear models were run to measure the association between symptom catastrophizing, cognitive variables, and their discrepancy, with affective distress as a covariate. RESULTS: Symptom catastrophizing was associated with more severe cognitive symptoms when controlling for neuropsychological performance (ß = 0.44, 95% CI [0.23, 0.65]). Symptom catastrophizing was also associated with higher subjective-objective cognition residuals (ß = 0.43, 95% CI [0.22, 0.64]). Catastrophizing remained a significant predictor after affective distress was introduced as a covariate. CONCLUSIONS: Catastrophizing is associated with misperceptions of cognitive functioning following mTBI, specifically overreporting cognitive symptoms relative to neuropsychological performance. Symptom catastrophizing may be an important determinant of cognitive symptom reporting months after mTBI. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Improvement of PbSn Solder Reliability with Ge Microalloying-Induced Optimization of Intermetallic Compounds Growth.

PbSn solders are used in semiconductor devices for aerospace or military purposes with high levels of reliability requirements. Microalloying has been widely adopted to improve the reliability for Pb-free solders, but its application in PbSn solders is scarce. In this article, the optimization of PbSn solder reliability with Ge microalloying was investigated using both experimental and calculation methods. Intermetallic compounds (IMC) growth and morphologies evolution during reliability tests were considered to be the main factors of device failure. Through first-principle calculation, the growth mechanism of interfacial Ni3Sn4 was discussed, including the formation of vacancies, the Ni-vacancies exchange diffusion and the dominant Ni diffusion along the [1 0 0] direction. The doping of Ge in the cell increased the exchange energy barrier and thus inhibited the IMC development and coarsening trend. In three reliability tests, only 0.013 wt% Ge microalloying in Pb60Sn40 was able to reduce IMC thickness by an increment of 22.6~38.7%. The proposed Ge microalloying method in traditional PbSn solder could yield a prospective candidate for highly reliable applications.

The Valorization of Wastes and Byproducts from Cruciferous Vegetables: A Review on the Potential Utilization of Cabbage, Cauliflower, and Broccoli Byproducts.

The management of vegetable waste and byproducts is a global challenge in the agricultural industry. As a commonly consumed vegetable crop, cruciferous vegetables marked higher amounts of wastage during their supply chain processes, with a significant contribution from cabbage, cauliflower, and broccoli. Therefore, the sustainable and resource-efficient utilization of discarded materials is crucial. This review explores potential applications of cruciferous vegetable waste and byproducts, spotlighting cabbage, cauliflower, and broccoli in food, medicinal, and other industries. Their significance of being utilized in value-added applications is addressed, emphasizing important biomolecules, technologies involved in the valorization process, and future aspects of practical applications. Cabbage, cauliflower, and broccoli generate waste and low-processing byproducts, including leaves, stems, stalks, and rot. Most of them contain high-value biomolecules, including bioactive proteins and phytochemicals, glucosinolates, flavonoids, anthocyanins, carotenoids, and tocopherols. Interestingly, isothiocyanates, derived from glucosinolates, exhibit strong anti-inflammatory and anticancer activity through various interactions with cellular molecules and the modulation of key signaling pathways in cells. Therefore, these cruciferous-based residues can be valorized efficiently through various innovative extraction and biotransformation techniques, as well as employing different biorefinery approaches. This not only minimizes environmental impact but also contributes to the development of high-value-added products for food, medicinal, and other related industries.

Symptoms of major depressive disorder and post-traumatic stress disorder in veterans with mild traumatic brain injury: A network analysis.

Mild Traumatic Brain Injury (mTBI, or concussion) is a debilitating condition that often leads to persistent cognitive and mental health problems post-injury. Post-traumatic Stress Disorder (PTSD) and Major Depressive Disorder (MDD) are two most commonly occurring mental health problems following mTBI and are suggested to be strong contributors to the persistent post-concussion symptoms. Thus, it is important to understand the symptomatology of PTSD and MDD post-mTBI, to better inform targets for behavioral health interventions. Therefore, the current study examined the symptom structure of post-mTBI co-morbid PTSD and MDD through network approaches; we compared the network structure of participants with a positive mTBI screen (N = 753) to the network structure of participants with a negative mTBI screen (N = 2044); lastly, we examined a network of PTSD and MDD symptoms with clinical covariates in a positive mTBI sample. We found that feeling distant/cutoff (P10) and difficulty concentrating (P15) were the most central symptoms in the positive mTBI network and sleep problems were the most prominent bridge nodes across the disorders. No significant difference between the positive and negative mTBI network were found through network comparison tests. Moreover, anxiety and insomnia were strongly associated with sleep symptoms and irritability symptoms, and emotional support and resilience were potential buffers against most of the PTSD and MDD symptoms. The results of this study might be particularly useful for identifying targets (i.e., feeling distant, concentration and sleep problems) for screening, monitoring and treatment after concussion to better inform post-mTBI mental health care and to improve treatment outcomes.

Combined treatment of lactic acid-ultrasound-papain on yak meat and its tenderization mechanism.

The combined effects of lactic acid-ultrasound-papain on yak meat tenderization were investigated, and its tenderization mechanism elucidated. The optimal condition for combined tenderization was obtained with 0.03% lactic acid, ultrasound for 30 mins, and 200 U/g of papain. When compared with the untreated yak meat, the cutting force and the cooking loss of the tenderized yak meat were decreased by 62.16% and 31.25%, respectively, while the myofibrillar fragmentation index increasing 4.3 times. After the combined tenderization, it was observed a loose arrangement of muscle with larger gaps and cavities. The random-coil content of myofibrillar protein increased to 48.3%, while α-helix decreased to 14.4%, indicating that the myofibrillar protein underwent some unfolding and stretching. These results demonstrated that this combined treatment improved the tenderization of yak meat by disrupting muscle integrity, increasing its water-holding capacity, denaturing myofibrillar protein, and changing its spatial structure. The combined process using lactic acid-ultrasound-papain showed some potential to improve meat texture.

Binding mechanism and bioavailability of a novel phosvitin phosphopeptide (Glu-Asp-Asp-pSer-pSer) calcium complex.

Phosvitin has excellent calcium binding capacity, related to its phosphopeptides. The phosphopeptides may be used as functional ingredients for improving calcium bioavailability, but the calcium-binding mechanism is unclear. In this study, a novel phosvitin phosphorylated pentapeptide (Glu-Asp-Asp-pSer-pSer, EDDpSpS) was selected to prepare an EDDpSpS calcium complex (EDDpSpS-Ca), and the calcium-binding mechanism and bioavailability investigated. The calcium-binding capacity of EDDpSpS was up to 468 ± 152.80 mg/g. Calcium ions prompted the folding of the EDDpSpS structure to form spherical nanoparticles. The calcium binding sites of EDDpSpS involved peptide bonds, carboxyl, amino, and phosphate groups. Molecular forces involved in these interactions were electrostatic in nature. Moreover, EDDpSpS-Ca had excellent bioavailability when compared to CaCO3, calcium lactate, and d-calcium gluconate. This study revealed the calcium-binding mechanism of phosvitin phosphopeptide, and suggested that EDDpSpS-Ca has the potential to be a novel, efficient, and promising calcium supplement.

Room temperature energy-efficient spin-orbit torque switching in two-dimensional van der Waals Fe3GeTe2 induced by topological insulators.

Two-dimensional (2D) ferromagnetic materials with unique magnetic properties have great potential for next-generation spintronic devices with high flexibility, easy controllability, and high heretointegrability. However, realizing magnetic switching with low power consumption at room temperature is challenging. Here, we demonstrate the room-temperature spin-orbit torque (SOT) driven magnetization switching in an all-van der Waals (vdW) heterostructure using an optimized epitaxial growth approach. The topological insulator Bi2Te3 not only raises the Curie temperature of Fe3GeTe2 (FGT) through interfacial exchange coupling but also works as a spin current source allowing the FGT to switch at a low current density of ~2.2×106 A/cm2. The SOT efficiency is ~2.69, measured at room temperature. The temperature and thickness-dependent SOT efficiency prove that the larger SOT in our system mainly originates from the nontrivial topological origin of the heterostructure. Our experiments enable an all-vdW SOT structure and provides a solid foundation for the implementation of room-temperature all-vdW spintronic devices in the future.

Extraction, characterization, and in vivo antitumor activity of a novel polysaccharide from Coriandrum sativum L.

A novel polysaccharide was extracted from Coriandrum sativum L. at a yield of 4.56 ± 0.17% (n = 3). The extraction was optimized using response surface methodology: powder-to-liquid ratio 1:21 g/ml, extraction time 188 min, temperature 81°C, and three replicate extractions. The purified polysaccharide had an average molecular weight of 1.30 × 106 Da and was composed of rhamnose, arabinose, galactose, glucose, and galacturonic acid in molar ratios of 1.52: 8.14: 20.85: 1: 2.42 with α-L-Araf-(1→, →6)-ß-D-Galp-(1→, →4)-α-GalpA-(1→ and →2, 4)-α-Rhap-(1→). In vivo tests demonstrated that the polysaccharide suppressed H22 tumor growth in mice and protected the immune organs. Annexin V-FITC/PI, PI, and JC-1 staining showed that the primary mechanism of tumor inhibition was the induction of apoptosis and S-phase arrest with apoptosis achieved via a mitochondrial pathway. PRACTICAL APPLICATIONS: Coriandrum sativum L. is used as a culinary spice but its medicinal value has also been widely recognized. A novel polysaccharide was extracted from this herbaceous plant and its structure and bioactivity were investigated. This high-molecular-weight polysaccharide exhibited antitumor effects against H22 cells in mice and had potential to be developed as an anti-liver cancer medicine and functional food supplement.

The Structural Characteristics of an Acidic Water-Soluble Polysaccharide from Bupleurum chinense DC and Its In Vivo Anti-Tumor Activity on H22 Tumor-Bearing Mice.

This study explored the preliminary structural characteristics and in vivo anti-tumor activity of an acidic water-soluble polysaccharide (BCP) separated purified from Bupleurum chinense DC root. The preliminary structural characterization of BCP was established using UV, HPGPC, FT-IR, IC, NMR, SEM, and Congo red. The results showed BCP as an acidic polysaccharide with an average molecular weight of 2.01 × 103 kDa. Furthermore, we showed that BCP consists of rhamnose, arabinose, galactose, glucose, and galacturonic acid (with a molar ratio of 0.063:0.788:0.841:1:0.196) in both α- and ß-type configurations. Using the H22 tumor-bearing mouse model, we assessed the anti-tumor activity of BCP in vivo. The results revealed the inhibitory effects of BCP on H22 tumor growth and the protective actions against tissue damage of thymus and spleen in mice. In addition, the JC-1 FITC-AnnexinV/PI staining and cell cycle analysis have collectively shown that BCP is sufficient to induce apoptosis and of H22 hepatocarcinoma cells in a dose-dependent manner. The inhibitory effect of BCP on tumor growth was likely attributable to the S phase arrest. Overall, our study presented significant anti-liver cancer profiles of BCP and its promising therapeutic potential as a safe and effective anti-tumor natural agent.

Spin-Orbit Torque Magnetization Switching in MoTe2 /Permalloy Heterostructures.

The ability to switch magnetic elements by spin-orbit-induced torques has recently attracted much attention for a path toward high-performance, nonvolatile memories with low power consumption. Realizing efficient spin-orbit-based switching requires the harnessing of both new materials and novel physics to obtain high charge-to-spin conversion efficiencies, thus making the choice of spin source crucial. Here, the observation of spin-orbit torque switching in bilayers consisting of a semimetallic film of 1T'-MoTe2 adjacent to permalloy is reported. Deterministic switching is achieved without external magnetic fields at room temperature, and the switching occurs with currents one order of magnitude smaller than those typical in devices using the best-performing heavy metals. The thickness-dependence can be understood if the interfacial spin-orbit contribution is considered in addition to the bulk spin Hall effect. Further threefold reduction in the switching current is demonstrated with resort to dumbbell-shaped magnetic elements. These findings foretell exciting prospects of using MoTe2 for low-power semimetal-material-based spin devices.

Nonlinear magnetotransport shaped by Fermi surface topology and convexity.

The nature of Fermi surface defines the physical properties of conductors and many physical phenomena can be traced to its shape. Although the recent discovery of a current-dependent nonlinear magnetoresistance in spin-polarized non-magnetic materials has attracted considerable attention in spintronics, correlations between this phenomenon and the underlying fermiology remain unexplored. Here, we report the observation of nonlinear magnetoresistance at room temperature in a semimetal WTe2, with an interesting temperature-driven inversion. Theoretical calculations reproduce the nonlinear transport measurements and allow us to attribute the inversion to temperature-induced changes in Fermi surface convexity. We also report a large anisotropy of nonlinear magnetoresistance in WTe2, due to its low symmetry of Fermi surfaces. The good agreement between experiments and theoretical modeling reveals the critical role of Fermi surface topology and convexity on the nonlinear magneto-response. These results lay a new path to explore ramifications of distinct fermiology for nonlinear transport in condensed-matter.

All-electric magnetization switching and Dzyaloshinskii-Moriya interaction in WTe2/ferromagnet heterostructures.

All-electric magnetization manipulation at low power is a prerequisite for a wide adoption of spintronic devices. Materials such as heavy metals1-3 or topological insulators4,5 provide good charge-to-spin conversion efficiencies. They enable magnetization switching in heterostructures with either metallic ferromagnets or with magnetic insulators. Recent work suggests a pronounced Edelstein effect in Weyl semimetals due to their non-trivial band structure6,7; the Edelstein effect can be one order of magnitude stronger than it is in topological insulators or Rashba systems. Furthermore, the strong intrinsic spin Hall effect from the bulk states in Weyl semimetals can contribute to the spin current generation8. The Td phase of the Weyl semimetal WTe2 (WTe2 hereafter) possesses strong spin-orbit coupling6,9 and non-trivial band structures10 with a large spin polarization protected by time-reversal symmetry in both the surface and bulk states9-11. Atomically flat surfaces, which can be produced with high quality12, facilitate spintronic device applications. Here, we use WTe2 as a spin current source in WTe2/Ni81Fe19 (Py) heterostructures. We report field-free current-induced magnetization switching at room temperature. A charge current density of ~2.96 × 105 A cm-2 suffices to switch the magnetization of the Py layer. With the charge current along the b axis of the WTe2 layer, the thickness-dependent charge-to-spin conversion efficiency reaches 0.51 at 6-7 GHz. At the WTe2/Py interface, a Dzyaloshinskii-Moriya interaction (DMI) with a DMI constant of -1.78 ± 0.06 mJ m-2 induces chiral domain wall tilting. Our study demonstrates the capability of WTe2 to efficiently manipulate magnetization and sheds light on the role of the interface in Weyl semimetal/magnet heterostructures.