Versatile mechanical properties of novel g-SiC x monolayers from graphene to silicene: a first-principles study.

Recently, a series of graphene-like binary monolayers (g-SiC x ), where Si partly substitutes the C positions in graphene, have been obtained by tailoring the band gaps of graphene and silicene that have made them a promising material for application in opto-electronic devices. Subsequently, evaluating the mechanical properties of g-SiC x has assumed great importance for engineering applications. In this study, we quantified the in-plane mechanical properties of g-SiC x (x = 7, 5, 3, 2 and 1) monolayers (also including graphene and silicene) based on density function theory. It was found that the mechanical parameters of g-SiC x , such as the ideal strength, Young's modulus, shear modulus, Poisson's ratio, as well as fracture toughness, are overall related to the ratio of Si-C to C-C bonds, which varies with Si concentration. However, for g-SiC7 and g-SiC3, the mechanical properties seem to depend on the structure because in g-SiC7, the C-C bond strength is severely weakened by abnormal stretching, and in g-SiC3, conjugation structure is formed. The microscopic failure of g-SiC x exhibits diverse styles depending on the more complex structural deformation modes introduced by Si substitution. We elaborated the structure-properties relationship of g-SiC x during the failure process, and in particular, found that the structural transformation of g-SiC3 and g-SiC is due to the singular symmetry of their structure. Due to the homogeneous phase, all the g-SiC x investigated in this study preserve rigorous isotropic Young's moduli and Poisson's ratios. With versatile mechanical performances, the family of g-SiC x may facilitate the design of advanced two-dimensional materials to meet the needs for practical mechanical engineering applications. The results offer a fundamental understanding of the mechanical behaviors of g-SiC x monolayers.

[Spontaneous spinal epidural hematoma: 2 cases]. / Hématome épidural rachidien spontané: 2 cas.

The authors report on two cases of spontaneous spinal epidural hematomas with atypical subacute clinical presentation and good recovery after surgical treatment. Etiologies, physiopathology, early diagnosis and treatment are considered through a brief review of the literature.

Effects of modified constraint-induced movement therapy on reach-to-grasp movements and functional performance after chronic stroke: a randomized controlled study.

OBJECTIVE: To evaluate changes in (1) motor control characteristics of the hemiparetic hand during the performance of a functional reach-to-grasp task and (2) functional performance of daily activities in patients with stroke treated with modified constraint-induced movement therapy. DESIGN: Two-group randomized controlled trial with pretreatment and posttreatment measures. SETTING: Rehabilitation clinics. SUBJECTS: Thirty-two chronic stroke patients (21 men, 11 women; mean age=57.9 years, range=43-81 years) 13-26 months (mean 16.3 months) after onset of a first-ever cerebrovascular accident. INTERVENTION: Thirty-two patients were randomized to receive modified constraint-induced movement therapy (restraint of the unaffected limb combined with intensive training of the affected limb) or traditional rehabilitation for three weeks. MAIN MEASURES: Kinematic analysis was used to assess motor control characteristics as patients reached to grasp a beverage can. Functional outcomes were evaluated using the Motor Activity Log and Functional Independence Measure. RESULTS: There were moderate and significant effects of modified constraint-induced movement therapy on some aspects of motor control of reach-to-grasp and on functional ability. The modified constraint-induced movement therapy group preplanned reaching and grasping (P=0.018) more efficiently and depended more on the feedforward control of reaching (P=0.046) than did the traditional rehabilitation group. The modified constraint-induced movement therapy group also showed significantly improved functional performance on the Motor Activity Log (P<0.0001) and the Functional Independence Measure (P=0.016). CONCLUSIONS: In addition to improving functional use of the affected arm and daily functioning, modified constraint-induced movement therapy improved motor control strategy during goal-directed reaching, a possible mechanism for the improved movement performance of stroke patients undergoing this therapy.

[Treatment of osteoarthritis of the carpometacarpal joint of the thumb by ligament reconstruction and tendon interposition arthroplasty]. / Tratamento da osteoartrose da base do polegar com artroplastia de interposição tendinosa e reconstrução ligamentar.

Total trapezium resection and palmar oblique ligament reconstruction combined with tendon interposition arthroplasty using the entire flexor carpi radialis tendon were performed in 21 patients (23 thumbs) who developed advanced osteoarthritis of the thumb basal joint. All patients were females and the age ranged from 42 to 73 years. Good results were achieved in 21 thumbs. These procedures improved pinch and grip strength and restored the thumb web space. No deterioration of function, instability or pain has been noted over the time.

[Helminth and pinworm control for primary school and kindergarten children by periodical mass-examination and treatment in Suan-Yuan District, Taipei (author's transl)].

The mass pre-control survey was done in fall semester 1978 by both methods that Kato's thick smear for helminthic infection and cellophane tape perianal swab for pinworm infection. There are about 19,000 primary school children and around 5,000 kindergarten children in Suan-yuan District, being the subjects. The helminthic positive rates (%) obtained were 5.18 and 3.81, respectively. The rates for pinworm were found 28.68% former and 29.00% for the latter. Drug was given to the egg-positive persons after mass examination, in each semester, for three consecutive years. Two broad-spectrum anthelmintics, pyrantel pamoate and mebendazole were used. The children who harbored Ascaris, hookworm or pinworm were given pyrantel tablet as a single dose of 10 mg/kg body weight, and whipworm positives were given a standard course of 100 mg of mebendazole twice daily for three days. After three-year operation, in accordance with the results of examination in Spring semester 1981, the egg positive rates were sharply dropped to 0.56% for the primary school children and 0.50% for the kindergarten. The pinworm infection rates for the above-mentioned group were also reduced to 13.05% and 18.68%, respectively.

Contribuição ao estudo anatômico do retalho ulnar distal do antebraço / Contribution to the anatomic study of the distal ulnar flap of the forearm

Os autores estudaram em 22 peças de cadáveres o retalho fasciocutâneo ulnar distaI do antebraço, baseado no ramo dorsal da artéria ulnar. Foi realizada a injeção de corante, sendo observada área corada dorsoulnar do punho e antebraço distal, medindo em média 8,25cm de largura por 17,13cm de comprimento. Foram estudados também o comprimento do ped¡culo vascular, seu diâmetro e a distância de sua emergência da artéria ulnar até o pisiforme. Este retalho encontra aplicação cl¡nica na reparação do revestimento cutâneo da face dorsal e volar do punho e da mão.