HCL: A Hierarchical Contrastive Learning Framework for Zero-Shot Relation Extraction.

Zero-shot relation extraction (ZSRE) is shown to become more significant in the current information extraction system, which aims at predicting relation classes that lack annotations or have just never appeared during training. Previous works focus on projecting sentences with their corresponding relation descriptions to an intermediate semantic space and searching the nearest semantic for predicting unseen classes. Though these methods can achieve sound performance, they only obtain inferior semantic information via a trivial distance metric and neglect the interaction in the instance representations. We are thus motivated to tackle these issues and propose a hierarchical contrastive learning (HCL) framework for ZSRE including projection-level and instance-level modules. Specifically, the projection-level component replaces the distance score function by contrastive loss to connect the input sentence with the relation semantic space. And the instance-level component integrates the external knowledge from sentence entities to establish new contrastive pairs for efficiently learning representations from mutual information. The experimental results on three well-known datasets demonstrate that our model surpasses the existing SOTA by at most 18.97% improvement on the F1 score when unseen classes are 15 . Moreover, our model can achieve more competitive performance alone with the increasing number of unseen classes.

Circularity in polymers: addressing performance and sustainability challenges using dynamic covalent chemistries.

The circularity of current and future polymeric materials is a major focus of fundamental and applied research, as undesirable end-of-life outcomes and waste accumulation are global problems that impact our society. The recycling or repurposing of thermoplastics and thermosets is an attractive solution to these issues, yet both options are encumbered by poor property retention upon reuse, along with heterogeneities in common waste streams that limit property optimization. Dynamic covalent chemistry, when applied to polymeric materials, enables the targeted design of reversible bonds that can be tailored to specific reprocessing conditions to help address conventional recycling challenges. In this review, we highlight the key features of several dynamic covalent chemistries that can promote closed-loop recyclability and we discuss recent synthetic progress towards incorporating these chemistries into new polymers and existing commodity plastics. Next, we outline how dynamic covalent bonds and polymer network structure influence thermomechanical properties related to application and recyclability, with a focus on predictive physical models that describe network rearrangement. Finally, we examine the potential economic and environmental impacts of dynamic covalent polymeric materials in closed-loop processing using elements derived from techno-economic analysis and life-cycle assessment, including minimum selling prices and greenhouse gas emissions. Throughout each section, we discuss interdisciplinary obstacles that hinder the widespread adoption of dynamic polymers and present opportunities and new directions toward the realization of circularity in polymeric materials.

Sustainability of Synthetic Plastics: Considerations in Materials Life-Cycle Management.

The sustainability of current and future plastic materials is a major focus of basic research, industry, government, and society at large. There is a general recognition of the positive impacts of plastics, especially packaging; however, the negative consequences around end-of-life outcomes and overall materials circularity are issues that must be addressed. In this perspective, we highlight some of the challenges associated with the many uses of plastic components and the diversity of materials needed to satisfy consumer demand, with several examples focused on plastics packaging. We also discuss the opportunities provided by conventional and advanced recycling/upgrading routes to petrochemical and bio-based materials and feedstocks, along with overviews of chemistry-related (experimental, computational, data science, and materials traceability) approaches to the valorization of polymers toward a closed-loop environment.

[Effect of acupuncture on migraine without aura: a resting-state functional magnetic resonance study].

OBJECTIVE: To observe therapeutic effect of acupuncture on migraine without aura and the changes of brain functional connectivity (FC) using resting-state functional magnetic resonance imaging (rs-fMRI). METHODS: Thirty-four patients with migraine without aura were included into an observation group and treated with acupuncture at Baihui (GV 20), Xuanlu (GB 5), Shuaigu (GB 8), Taiyang (EX-HN 5), etc. Using G6805-Ⅱ electric acupuncture apparatus, the ipsilateral Fengchi (GB 20) and Shuaigu (GB 8) were connected and stimulated with continuous wave, 2 Hz in frequency and 0.1 mA to 1.0 mA in current intensity, depending on patient's tolerance. Acupuncture stimulation lasted 20 min each time, twice weekly (at the interval>2 days). A total of 6 weeks of treatment (12 times) was required. Matching the gender and age as those of the observation group, 16 healthy subjects were recruited into a control group and no any intervention was provided. The headache days, the score of visual analogue scale (VAS) for headache severity, the total score of headache symptoms, the score of migraine-specific quality of life questionnaire (MSQ), the score of self-rating anxiety scale (SAS), and the score of self-rating depression scale (SDS) were compared before and after acupuncture, and the clinical efficacy was assessed in the observation group. The data of the resting-state functional magnetic resonance were collected in the observation group before and after treatment as well as the control group at baseline. The periaqueductal gray (PAG) was taken as the seed to analyze the effect of acupuncture on the brain FC and the correlation between FC and VAS scores, headache days in the patients of migraine without aura. RESULTS: After treatment, the headache days, VAS score, the total score of headache symptoms, SAS score and SDS score were all reduced (P<0.01); and the scores of the restrictive, preventive, and emotional functional domains of the MSQ were increased (P<0.01) in the observation group compared with those before treatment. The total effective rate was 94.1% (32/34). Compared with the control group, FC between PAG and the right cerebellum Ⅷ was decreased in the observation group before treatment (P<0.05). FC of PAG with the bilateral cerebellum Ⅷ and the left precuneus was increased in the observation group after treatment compared with those before treatment (P<0.05). In the observation group, the FC intensity of PAG and the right cerebellum Ⅷ was negatively correlated with VAS score (r =-0.41, P<0.05) before treatment, while the FC intensity of PAG and the left precuneus was positively correlated with the improvement in headache days (r =0.40, P<0.05) after treatment. CONCLUSION: Acupuncture is effective on migraine without aura. The brain functional connectivity is abnormal in the patients. The effect onset of acupuncture is obtained probably by regulating the abnormal brain regions and activating brain regions relevant with pain and emotions.

Differential Modulating Effect of Acupuncture in Patients With Migraine Without Aura: A Resting Functional Magnetic Resonance Study.

Introduction: Migraine is a recurrent neurological disorder, the symptoms of which can be significantly relieved by acupuncture. However, the central mechanism via which acupuncture exerts its therapeutic effect in migraine is unclear. The aim of this study was to compare the differences in regional homogeneity (ReHo) between patients with migraine without aura (MwoA) and healthy controls (HCs) and to explore the immediate and cumulative therapeutic effect of acupuncture in patients with MwoA using resting-state functional magnetic resonance imaging (fMRI). Methods: The study subjects were 40 patients with MwoA and 16 matched HCs. The patients with MwoA received acupuncture on 2 days per week for 6 weeks for a total of 12 sessions followed by 24 weeks of follow-up. The primary clinical efficacy outcomes were the number of days with migraine and the average severity of headache. Secondary outcomes were the Migraine-Specific Quality of Life Questionnaire, Self-Rating Anxiety Scale, and Self-Rating Depression Scale scores. In the migraine group, resting-state blood-oxygen-level-dependent fMRI scans were obtained at baseline and after the first and 12th acupuncture sessions to measure the ReHo value. In the HCs, only a baseline resting-state blood-oxygen-level-dependent fMRI scan was obtained. Results: Compared with the control group, the migraine group had a significantly lower ReHo value in the cerebellum, which increased after the first acupuncture session. Long-term acupuncture significantly improved migraine symptoms and mood with a therapeutic effect that lasted for at least 6 months. After 12 acupuncture sessions, there were significant increase of cerebellum and angular gyrus in the migraine group. Conclusion: These findings suggest that migraine is related to cerebellar dysfunction. Acupuncture can relieve the symptoms of migraine, improve dysfunction of cerebellum, and activate brain regions involved in modulation of pain and emotion The cumulative therapeutic effect of acupuncture is more extensive and significant than its immediate effect.

Amphiphilic Triblock Copolymers Containing Polypropylene as the Middle Block.

The synthesis of stereoregular telechelic polypropylene (PP) and their use to access triblock amphiphilic copolymers with the PP block located in the center is described. The strategy consists of selectively copolymerizing propylene and a di-functional co-monomer (1,3-diisopropenylbenzene) to yield a α,ω-substituted polypropylene. Initiation of the copolymerization favors insertion of DIB over propylene; propagation steps favor insertion of propylene. Termination via a chain-transfer reaction yields the terminal unsaturation of the polymer. The telechelic polypropylene is then converted into α,ω-hydroxyl-terminated polypropylene and used as a macroinitiator for the synthesis of triblock copolymers. Water-soluble amphiphilic triblock polymers are also synthesized. The use of catalytic reactions simultaneously provides the stereocontrol of the polypropylene and high productivity (multiple chains of block copolymer per metal center).

[Rolling needle pricking-cupping therapy and traditional pricking-cupping therapy for cervical spondylosis of neck type: a randomized controlled trial].

OBJECTIVE: To compare the clinical efficacy between rolling needle pricking-cupping (RNP-C) and traditional pricking-cupping (TP-C) for cervical spondylosis of neck type. METHODS: A total of 96 patients with cervical spondylosis of neck type were randomly divided into an RNP-C group, a TP-C group and an electroacupuncture (EA) group, 32 cases in each group. Each group was treated with EA at Jingbailao (EX-HN 15), Fengchi (GB 20), Dazhui (GV 14), Jianjing (GB 21) and ashi points with continuous wave and 2 Hz of frequency; each EA treatment lasted for 20 min, once every 3 to 5 days, totaling 6 treatments. On the basis of EA treatment, the patients in the TP-C group were treated with bloodletting by seven-star needle, followed by fire cupping; the patients in the RNP-C group were treated with bloodletting by rolling needle, followed by fire cupping. The treatment was given once a week for 4 weeks. The follow-up was 1 month. Before treatment, 2 and 4 weeks into treatment and follow-up, the Northwick Park neck-pain questionnaire (NPQ) and visual analogue scale (VAS) scores were evaluated. The acupuncture pain degree was recorded at the first treatment and 2 and 4 weeks into treatment. The efficacy was evaluated after 4 weeks of treatment. RESULTS: Compared before treatment, the scores of NPQ and VAS in each group were all reduced at 2 and 4 weeks into treatment and follow-up (P<0.05). The scores of NPQ in the TP-C group and the RNP-C group were lower than those in the EA group at 2 and 4 weeks into treatment (P<0.05). The scores of VAS in the TP-C group and the RNP-C group were lower than those in the EA group at 2 and 4 weeks into treatment and follow-up (P<0.05). The differences of NPQ and VAS scores between the TP-C group and the RNP-C group at each time point after treatment were not significant (P>0.05). The acupuncture pain degree in the RNP-C group was lower than that in the TP-C group (P<0.05). The total effective rates were 79.3% (23/29) in the TP-C group and 75.0% (24/32) in the RNP-C group, which was superior to 63.3% (19/30) in the EA group (P<0.05), but there was no statistical significance between the TP-C group and the RNP-C group (P>0.05). CONCLUSION: TP-C and RNP-C could both improve the cervical pain symptoms in patients with cervical spondylosis of neck type, and improve the overall function of the cervical spine, and the curative effect is similar.

Laser-induced interstitial thermotherapy via a single-needle delivery system: Optimal conditions of ablation, pathological and ultrasonic changes.

This study aimed to examine the optimal conditions of laser-induced interstitial thermotherapy (LITT) via a single-needle delivery system, and the ablation-related pathological and ultrasonic changes. Ultrasound (US)-guided LITT (EchoLaser system) was performed at the output power of 2-4 Wattage (W) for 1-10 min in ex vivo bovine liver. Based on the results of the ex vivo study, the output power of 3 and 4 W with different durations was applied to in vivo rabbit livers (n=24), and VX2 tumors implanted in the hind limbs of rabbits (n=24). The ablation area was histologically determined by hematoxylin-eosin (HE) staining. Traditional US and contrast enhanced ultrasound (CEUS) were used to evaluate the treatment outcomes. The results showed: (1) In the bovine liver, ablation disruption was grossly seen, including a strip-like ablation crater, a carbonization zone anteriorly along the fiber tip, and a surrounding gray-white coagulation zone. The coagulation area, 1.2 cm in length and 1.0 cm in width, was formed in the bovine liver subjected to the ablation at 3 W for 5 min and 4 W for 4 min, and it extended slightly with the ablation time. (2) In the rabbit liver, after LITT at 3 W for 3 min and more, the coagulation area with length greater than or equal to 1.2 cm, and width greater than or equal to 1.0 cm, was found. Similar coagulation area was seen in the implanted VX2 carcinoma at 3 W for 5 min. (3) Gross examination of the liver and carcinoma showed three distinct regions: ablation crater/carbonization, coagulation and congestion distributed from the center outwards. (4) Microscopy revealed four zones after LITT, including ablation crater/carbonization, coagulation, edema and congestion from the center outwards. A large area with coagulative necrosis was observed around a vessel in the peripheral area with edema and hyperemia. (5) The size of coagulation was consistent well to the CEUS findings. It was concluded that EchoLaser system at low power can produce a coagulation area larger than 1.0 cm×1.0 cm during a short time period. The real-time US imaging can be used to effectively guide and assess the treatment.

Toward High Performance n-Type Thermoelectric Materials by Rational Modification of BDPPV Backbones.

Three n-type polymers BDPPV, ClBDPPV, and FBDPPV which exhibit outstanding electrical conductivities when mixed with an n-type dopant, N-DMBI ((4-(1,3-dimethyl-2,3-dihydro-1H-benzoimidazol-2-yl)phenyl)dimethylamine), in solution. High electron mobility and an efficient doping process endow FBDPPV with the highest electrical conductivities of 14 S cm(-1) and power factors up to 28 µW m(-1) K(-2), which is the highest thermoelectric (TE) power factor that has been reported for solution processable n-type conjugated polymers. Our investigations reveal that introduction of halogen atoms to the polymer backbones has a dramatic influence on not only the electron mobilities but also the doping levels, both of which are critical to the electrical conductivities. This work suggests the significance of rational modification of polymer structures and opens the gate for applying the rapidly developed organic semiconductors with high carrier mobilities to thermoelectric field.

Wave intensity analysis of carotid artery: a noninvasive technique for assessing hemodynamic changes of hyperthyroid patients.

This study examined the wave intensity (WI) of the carotid artery in patients with hyperthyroid in order to assess the hemodynamic changes of hyperthyroid patients. A total of 86 hyperthyroid patients without cardiac morphological changes and arrhythmia, and 80 healthy control subjects were enrolled in the study. Right common carotid artery (RCCA) was selected for ultrasonic imaging to obtain WI indices, including amplitude of the peak during early systole (W1), amplitude of the peak during late systole (W2), area of the negative wave during mid-systole (NA), interval between R wave of electrocardiogram and W1 (R-1st), interval between W1 and W2 (1st-2nd). The levels of serum thyroid hormones, consisting of free triiodothyronine (FT3), free thyroxin (FT4) and thyroid stimulating hormone (TSH), were measured in hyperthyroid patients. Echocardiographic indices including left ventricular ejection fraction (LVEF) and left ventricular fraction shortening (LVFS) were determined in each subject. The results showed that the W1, W2, NA, and (1st-2nd×HR) in hyperthyroid patients were significantly higher than those in healthy controls. There was no significant difference in LVEF and LVFS between the two groups. FT3 was correlated with W1, W2, NA, (1st-2nd×HR), pulse pressure (PP) and heart rate (HR) in hyperthyroid patients. Several abnormal waves on WI curves were present in 19 hyperthyroid patients during mid-systole. It was concluded that WI technique may prove a real-time, noninvasive, sensitive and convenient tool for assessing the cardiac function and hemodynamic alterations in hyperthyroid patients.

Wave Intensity Analysis of Carotid Artery: A Noninvasive Technique for Assessing Hemodynamic Changes of Hyperthyroid Patients / 华中科技大学学报（医学）（英德文版）

This study examined the wave intensity (WI) of the carotid artery in patients with hyperthyroid in order to assess the hemodynamic changes of hyperthyroid patients. A total of 86 hyperthyroid patients without cardiac morphological changes and arrhythmia, and 80 healthy control subjects were enrolled in the study. Right common carotid artery (RCCA) was selected for ultrasonic imaging to obtain WI indices, including amplitude of the peak during early systole (W1), amplitude of the peak during late systole (W2), area of the negative wave during mid-systole (NA), interval between R wave of electrocardiogram and W1 (R-1 st), interval between W1 and W2 (1 st-2nd). The levels of serum thyroid hormones, consisting of free triiodothyronine (FT3), free thyroxin (FT4) and thyroid stimulating hormone (TSH), were measured in hyperthyroid patients. Echocardiographic indices including left ventricular ejection fraction (LVEF) and left ventricular fraction shortening (LVFS) were determined in each subject. The results showed that the WI, W2, NA, and (lst-2nd×HR) in hyperthyroid patients were significantly higher than those in healthy controls. There was no significant difference in LVEF and LVFS between the two groups. FT3 was correlated with WI, W2, NA,(lst-2nd×HR), pulse pressure (PP) and heart rate (HR) in hyperthyroid patients. Several abnormal waves on WI curves were present in 19 hyperthyroid patients during mid-systole. It was concluded that WI technique may prove a real-time, noninvasive, sensitive and convenient tool for assessing the cardiac function and hemodynamic alterations in hyperthyroid patients.

Early detection of lesions of dorsal artery of foot in patients with type 2 diabetes mellitus by high-frequency ultrasonography.

This study evaluated the value of high-frequency ultrasonograpy for early detection of dorsal artery of foot in patients with type 2 diabetes mellitus (MD). Eighty subjects including 40 patients with type 2 MD (T2DM group) and 40 healthy volunteers (NC group) were recruited. The intima-media thickness (IMT), the inner diameter and the perfusion of dorsal artery of foot were measured by using high-frequency ultrasonograpy. Meanwhile, the parameters of vascular elasticity, including stiffness parameter (beta), pressure-strain elastic modulus (Erho), arterial compliance (AC), augment index (AI), and pulse wave conducting velocity (PWVbeta) were detected by means of echo-tracking technique. The results showed that no significant difference was found in the IMT, systolic diameter (Ds), diastolic diameter (Dd) and peak systolic velocity (PSV) between T2DM and NC groups. Erho and PWVbeta were increased, and AC was decreased in T2DM group as compared with those in NC group with the differences being significant (P<0.05 for all). There was no significant difference in beta and AI between T2DM and NC groups. It was concluded that high-frequency ultrasonography in combination with echo-tracking technique is sensitive and non-invasive, and can be used for early detection of sclerosis of the lower extremity artery in patients with type 2 MD.

Early Detection of Lesions of Dorsal Artery of Foot in Patients with Type 2 Diabetes Mellitus by High-frequency Ultrasonography / 华中科技大学学报（医学）（英德文版）

lerosis of the lower extremity artery in patients with type 2 MD.