bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chain Links Under Cross Forces
Authors: Reynolds Jos. B. 
Published: March 2021

Abstract
This paper develops theory for stresses and deflections of links with circular neutral axes when freely supported at the ends of one diameter and loaded with two equal loads, perpendicular to the plane of the neutral axis, at the ends of the diameter perpendicular to the first. It also develops theory for deflections of oblong links whose neutral axes consist of semicircles connected by straight sides when supported at the middle points of the end arcs and loaded with equal loads perpendicular to the plane of the neutral axis at the midpoints of the sides. The theory is checked by experimental tests.
Critical-Speed Behavior of Unsymmetrical Shafts
Authors: Taylor H. D. 
Published: March 2021

Abstract
The development of large two-pole turbine generators with rotors running above the critical speed, and having long core bodies slotted for field coils, makes desirable a working familiarity with the vibrational characteristics of unsymmetrical shafts. It is the purpose of this paper to describe these characteristics which are distinctly peculiar. This problem has received some attention from previous writers (6-9), who have pointed out an unstable range of operation due to dissymmetry of the shaft, and some of whom made small-scale tests for demonstration. In the present investigation, experimental work on a special rotor of 10 1/2 ft span and weighing over 5000 lb was carried out, to test in some detail the indications of a thorough analysis of the problem by the late V. Petrovsky of the Lynn Works of the General Electric Co. This analysis is given in outline in an Appendix.
The first part of the paper deals briefly with the static characteristics of unsymmetrical shafts, as a basis for defining the “degree of dissymmetry.” The critical-speed behavior of ordinary round shafts is then reviewed and the theoretical differences due to dissymmetry are described. These are: (a) With moderate dissymmetry compared with the degree of damping, a marked increase in the critical-speed amplitude, and a pronounced variation in the amplitude with the angular position of the unbalance of the rotor; (b) with greater dissymmetry, beyond a limiting value, an infinite critical-speed amplitude, or rather, two infinite peaks, with unstable operation between them; (c) considerable distortion of the phase-angle curves, such that in general the phase angle may be much larger or smaller than 90 deg at the critical speed; (d) double-frequency vibration, if the shaft is horizontal, with an auxiliary peak, or “subcritical” at half the main critical speed.
Tests on the 5000-lb rotor are described which give general confirmation of these characteristics.
The Impact of a Mass Striking a Beam
Authors: Lee E. H. 
Published: March 2021

Abstract
The integral equation for the horizontal impact of a mass on a beam was developed by Timoshenko in 1912. He showed that any such impact problem can be solved provided sufficient patience and tenacity are applied in using the tedious numerical method of solution by dividing the time into small increments during which the contact force can be considered constant. This method is too lengthy to be applied in practice, and moreover, a solution is required giving characteristics of the impact as a whole, rather than slowly progressing through its duration with no indication of the future development of the impact.
In the first part of this paper a concise approximate solution is developed, making the assumptions that the duration of contact is small in comparison with the period of the fundamental mode of vibration of the beam, and that only the fundamental mode of oscillation of the beam need be considered. Results obtained by this method are checked against those determined by the lengthier numerical method. Good agreement is reached in some examples, but other results show large errors, both in the contact compression force and in the resulting motion.
Light was brought to bear on this difficulty by using a solution based on energy and momentum considerations, giving a curve which supplies a rapid determination of the distribution of energy among the various modes of vibration of the beam. This curve gives directly the condition for the vibrational energy developed in the beam, due to the impact, to be confined mainly to the fundamental mode. This is shown by examples to be the required condition for the validity of the previous approximate method.
The solution using energy and momentum considerations is developed to give the motions of the beam and mass resulting from the impact (free vibrations in the beam and uniform velocity of the mass) so that the subsequent development of the impact can be ascertained and repeated impacts dealt with. The investigation also gives the deflection curves of the beam produced by the impact; these show a wide deviation from static-deflection curves.
Some Observations on the Theory of Contact Pressures
Authors: Way Stewart 
Published: March 2021

Abstract
The stress system in a semi-infinite elastic solid with given normal surface loading is of importance in many problems of machine and structural design and strength of materials. It often happens in such cases that the stresses in which one is primarily interested are those in the surface of the body. This paper presents some observations that can be made regarding the stresses and displacements in the surface.
Combustion and Emissions of a Gas-to-Liquid Diesel Engine Utilizing Optimized Spiral-Helical Intake Manifold Designs
Authors: Abdellatif Yasser M. , Saker Ahmad T. , Elbashir Aboubaker M. , Ahmed Samer F. 
Published: March 2021

Abstract
Two simultaneous strategies were used to reduce diesel engine emissions. Optimized manifold designs were used with gas-to-liquid (GTL) fuel and its blend with diesel fuel. Six new spiral-helical manifolds were tested, which could be divided into two groups. The first group is with the same inner diameter (2.6 cm) and outlet angle (30 deg), but the different number of spiral turns (1t, 2t, etc.). The second group is with different inner diameters. The results showed that the highest pressure and heat release were achieved by m(2.6,30,1t) with the diesel–GTL blend. In addition, the heat release rate decreases with the increase in the number of turns. The same combination also reduced the pressure rise rate (dP/dθ) by about 24% compared to the normal manifold. For the emissions, the maximum reduction in CO emissions was achieved by using m(2.6,30,3t) and GTL with about 34%. In addition, the maximum hydrocarbon (HC) reduction was achieved by m(2.1,30,3t) and GTL, which is about 99% lower than that of the normal manifold. NO emissions were reduced by about 25% when m(2.6,30,4t) and GTL are used. The total particulate matters (PM) were the lowest for m(2.6,30,1t) and normal manifold in the case of diesel. Generally, it was found that the combination of m(2.6,30,1t) with GTL and its blend gave the optimum performance and low emissions among all manifolds.
Numerical Investigation Into the Effect of Structural Parameters of Parallel Flow Field With Cooling Channels on Fuel Cell Performance
Authors: Li Chen , Xu Xiaoming , Hu Hao , Mei Nan , Yang Yi 
Published: March 2021

Abstract
The electrochemical reaction inside a high-power fuel cell generates a lot of heat. Excessive heat affects the performance of the membrane, so it is necessary to introduce coolant. The main objective of coolant is regulating the temperature of relatively high-power proton exchange membrane fuel cell (PEMFC) stacks efficiently. The coolant channel has a great influence on the performance of PEMFC. In this work, a multiphase, 3D PEMFC model with serpentine flow channel is developed. In order to rank structural parameters according to the degree of influence on fuel cell performance, this study analyzed the current density, O2 mass fraction, and the distributions of temperature based on an orthogonal test scheme with three factors and three levels. The results show that rib width between the reactant flow channel and the cooling channel has the greatest influence on the current density, and gas flow channel width has the least influence.
Acupuncture and moxibustion stimulate fibroblast proliferation and neoangiogenesis during tissue repair of experimental excisional injuries in adult female Wistar rats
Authors: Alonso Hamilton Ricardo , Kuroda Fabricio Campos , Passarini Junior José Roberto , Quispe Cabanillas Juan Guzman , Mendonça Fernanda Aparecida Sampaio , dos Santos Glaucia Maria Tech , de Aro Andrea Aparecida , do Amaral Maria Esméria Corezola , Marretto Esquisatto Marcelo Augusto 
Published: March 2021

Objective: To investigate the effects of acupuncture and moxibustion on the repair of excisional skin injuries on the back of adult female Wistar rats. Methods: 90 animals were divided into three groups: C, control; A, acupuncture treatment (needled at traditional acupuncture points BL13, BL17 and ST36); M, moxibustion treatment (overlying same traditional acupuncture points). They were euthanased on days 7, 14 and 21 after injury for removal and preparation of tissue for analysis. Results: The treated groups (A and M) showed no changes regarding the structural analysis relative to the control (C) group. The total number of fibroblast cells in the A and M groups were significantly higher than those in the C group on days 14 and 21. The number of granulocytes was significantly less in the A and M groups compared with the C group on days 14 and 21. The total number of newly formed vessels increased on day 21 and was significantly higher in the A and M groups. The amount of birefringent collagen fibre detected on day 21 was significantly higher in the C group. The amount of glycosaminoglycan and hydroxyproline was similar between the groups. The amount of collagen I did not differ between the groups in any period, despite the increased amount detected over time. The amount of type III collagen did not differ between the groups but the detected amount decreased over the course of the experiment. The amount of transforming growth factor β1 (TGF-β1) and vascular endothelial growth factor (VEGF) in the A and M rats was similar but inferior to C rats across all experimental periods. Conclusions: Acupuncture and moxibustion stimulated fibroblast proliferation and neoangiogenesis, and extended the period of collagen fibre reorganisation in the repair of excisional injuries in adult female rats.
Moxibustion at CV4 alleviates atherosclerotic lesions through activation of the LXRα/ABCA1 pathway in apolipoprotein-E-deficient mice
Authors: Cui Yingxue , Liu Juntian , Huang Chang , Zhao Baixiao 
Published: March 2021

Objectives: To investigate the anti-atherogenic effect of moxibustion and whether it is mediated through the reverse cholesterol transport process. Methods: 8-week-old male apolipoprotein E deficient (ApoE−/− knockout) mice were randomly divided into two groups (n=10 per group): atherosclerosis (AS) and AS plus moxibustion (AS+M). C57BL/6J mice of the same background (n=10) were selected as controls. Mice in the AS+M group received indirect moxibustion with an ignited moxa stick held over CV4. Mice of the AS and control groups were restrained in the same holder with an unlit moxa stick held over CV4. All treatments were performed for 20 min per day, 6 days per week for 12 weeks. After the treatment, the mice were euthanased and their serum lipids were measured. The aortic roots and thoracic aortas were collected for haematoxylin and eosin and red oil O staining, respectively, to analyse the atherosclerotic lesions. Expression of adenosine triphosphate binding cassette (ABCA)A1/G1 and liver X receptor α (LXRα) in the thoracic aorta were examined with Western blotting. Results: The moxibustion-treated (AS+M) mice showed a significantly lower plaque area percentage in the aortic root and thoracic aorta, and higher expression of LXRα and ABCA1 in the thoracic aorta compared with the AS mice. No significant differences were found in average lipid area percentage in the thoracic aorta, or ABCG1 expression in the thoracic aorta, between mice in the AS+M and AS groups. Conclusion: Moxibustion treatment at CV4 suppressed the progression of atherosclerotic lesions in ApoE−/− mice. The anti-atherogenic effect of moxibustion may be achieved by: (1) regulation of lipid metabolism, and thus prevention of lipid accumulation; and (2) upregulation of LXRα- and ABCA1-mediated cholesterol efflux in the lesion area.
Factor analysis of electroacupuncture and selective serotonin reuptake inhibitors for major depressive disorder: an 8-week controlled clinical trial
Authors: Yang Xinjing , Gong Weijun , Ma Xuehong , Wang Sihan , Wang Xueqin , Guo Tianwei , Guo Zhuo , Sun Yang , Li Jing , Zhao Bingcong , Tu Ya 
Published: March 2021

Background: There is evidence supporting electroacupuncture (EA) for the treatment of major depressive disorder (MDD), but its characteristics have not been well investigated. Objective: To investigate the effectiveness and characteristics of EA in MDD. Methods: 60 subjects were enrolled—35 in the EA group and 25 in the selective serotonin reuptake inhibitor (SSRI) group based on their preferences—in an 8-week non-randomised controlled clinical trial. The 24-item Hamilton depression rating scale (HAMD-24) and clinical global impression (CGI) were adopted for clinical assessment. The Columbia suicide severity rating scale and adverse event form were used to measure safety and tolerability. The characteristics of EA and SSRIs were compared by analysing seven factors of the HAMD-24. Results: There was no significant difference between the two groups in terms of HAMD-24 response rate after intervention (P>0.05). Patients treated with EA demonstrated a significant reduction in CGI scores (P<0.05) with fewer adverse events compared with SSRIs (P<0.01). Although HAMD-24 factor analysis showed both EA and SSRIs could improve factor scores in cognitive impairment, diurnal variation, retardation, sleep disturbance, anxiety/somatisation and feelings of despair, EA showed greater improvement in anxiety/somatisation and feelings of despair than SSRIs (P<0.05). Conclusions: There was no significant difference between EA and SSRIs in the treatment of MDD with respect to our primary outcome. However, as a potential therapy for MDD, EA appeared to result in greater symptom improvement than SSRI treatment with respect to anxiety/somatisation and feelings of despair. The results of this secondary analysis should be interpreted cautiously given the inherent issues of multiple testing.
Influence of electroacupuncture stimulation on skin temperature, skin blood flow, muscle blood volume and pupil diameter
Authors: Kubota Tomoko , Mori Hidetoshi , Morisawa Tateyuki , Hanyu Kazuyo , Kuge Hiroshi , Watanabe Mayumi , Tanaka Tim H 
Published: March 2021

Objective: To examine the effect of electroacupuncture (EA) stimulation on multiple physiological indices and to evaluate both local and systemic physiological responses induced by the stimulation. Methods: 15 healthy male college students participated in an experimental crossover study. They received two kinds of interventions: one with EA stimulation and one without EA stimulation on different days. Two disposable acupuncture needles were inserted at two traditional acupuncture points (ST36 and ST38), located along the anterior tibialis muscle. EA stimulation was administered for 10 min. Skin temperature (ST), skin blood flow (SBF) and muscle blood volume (MBV) were recorded near the stimulation sites, while the pupil diameter (PD) was measured before, during and after the interventions. Results: ST, SBF and MBV increased significantly following EA stimulation. PD of the right and left eyes decreased significantly following EA stimulation. There was a significant difference in ST responses between the groups (P=0.001). For SBF, MBV and PD, no significant differences were demonstrated between the groups. Conclusions: Our study showed that 10 min of EA stimulation increased ST, SBF and MBV, and decreased PD, compared to baseline, while no significant change was observed in the control group. This suggests that EA stimulation alters local blood flow and ST, and these responses are likely mediated via segmental spinal reflexes, supraspinal reflexes involving parasympathetic activation, and other mechanisms.
Evidence of efficacy of acupuncture in the management of low back pain: a systematic review and meta-analysis of randomised placebo- or sham-controlled trials
Authors: Xiang Yan , He Jin-yuan , Tian Huan-huan , Cao Bing-yan , Li Rui 
Published: March 2021

Objectives: To assess the evidence for the efficacy of acupuncture for non-specific low back pain (NSLBP), compared with sham or placebo therapies. Methods: We searched Cochrane CENTRAL to December 2016, and conducted searches from 1980 to December 2016 in PubMed, MEDLINE and Embase. There were no regional restrictions applied. We included only randomised controlled trials of adults with NSLBP. Placebo/sham procedures were required of the control interventions. The trials were combined using meta-analysis when the data reported allowed for statistical pooling. Results: 14 trials (2110 participants) were included in the review, and 9 were included in the meta-analysis. Immediately after the acupuncture treatment we found statistically significant differences in pain reduction between acupuncture and sham or placebo therapy (standardised mean difference (SMD) −0.40, 95% CI −0.54 to −0.25; I2 7%; 753 participants; 9 studies), but there were no differences in function (weighted mean difference (WMD) −1.05, 95% CI −3.61 to 1.52; I2 79%; 462 participants; 4 studies). At follow-up, there were significant differences in pain reduction (SMD −0.46, 95% CI −0.82 to −0.09; I2 67%), but not in function (WMD −0.98, 95%CI −3.36 to 1.40; I2 87%). We conducted subgroup analyses both immediately after treatment and at follow-up. Conclusion: There is moderate evidence of efficacy for acupuncture in terms of pain reduction immediately after treatment for NSLBP ((sub)acute and chronic) when compared to sham or placebo acupuncture. Registration: PROSPERO registration no. CRD42017059438.
Toll-like receptor 2 plays an essential role in electroacupuncture analgesia in a mouse model of inflammatory pain
Authors: Hsu Hsin-Cheng , Hsieh Ching-Liang , Wu Shu-Yih , Lin Yi-Wen 
Published: March 2021

Background: Inflammatory pain occurs when local tissue injury activates macrophages and neutrophils, hence increasing pro-inflammatory cytokine and chemokine levels. Toll-like receptor 2 (TLR2) antagonism reportedly suppresses neuropathic and inflammatory pain. Aims: In the present study, we investigated the effect of electroacupuncture (EA) on TLR2 and related signalling molecules in a complete Freund’s adjuvant (CFA)-induced mouse model of inflammatory pain to determine whether EA can attenuate inflammatory pain via the TLR2 signalling pathway. Methods: EA significantly reduced mechanical and thermal hyperalgesia in the animal model. A similar effect was produced by TLR2 antagonism induced by CU-CPT22 injection. Results: TLR2 expression in the dorsal root ganglia, spinal cord and thalamus increased following induction of inflammation. Expression levels of downstream molecules such as pPI3K, pAkt and pmTOR also increased, as did those of MAPK subfamily members such as pERK, pp38 and pJNK. Transcription factors (pCREB and pNFκB) and nociceptive ion channels (Nav1.7 and Nav1.8) were also involved. Conclusion: Increased expression of the above molecules was attenuated by both EA and TLR2 antagonism. Our results show that EA attenuates inflammatory pain via TLR2 signalling.
Effects of GB34 acupuncture on hyperventilation-induced carbon dioxide reactivity and cerebral blood flow velocity in the anterior and middle cerebral arteries of normal subjects
Authors: Moon Sang-Kwan , Kwon Seungwon , Cho Seung-Yeon , Park Seong-Uk , Jung Woo-Sang , Park Jung-Mi , Ko Chang-Nam , Cho Ki-Ho , Son Jeong-Hwa 
Published: March 2021

Objectives: To determine whether acupuncture at GB34 affects cerebral blood flow (CBF) via the anterior cerebral arteries (ACAs) and middle cerebral arteries (MCAs). Methods: This study included 10 healthy young male volunteers. CBF velocity and cerebrovascular reactivity (CVR) were measured using transcranial Doppler sonography (TCD). The changes in hyperventilation-induced carbon dioxide (CO2) reactivity and modified blood flow velocity at 40 mm Hg (CV40) were observed for both ACAs and MCAs before and after GB34 acupuncture treatment. Blood pressure and heart rate were also measured before and after GB34 acupuncture treatment. Results: The CO2 reactivity of the ipsilateral MCA significantly increased after GB34 acupuncture treatment, compared with that at baseline (P=0.007). In contrast, the CO2 reactivity of both ACAs and the contralateral MCA remained unchanged. The CV40 of both ACAs and MCAs did not change after GB34 acupuncture treatment and neither did the mean arterial blood pressure and heart rate. Conclusions: GB34 acupuncture treatment increased CO2 reactivity specifically in the ipsilateral MCA, but had no effect on either the ACAs or the contralateral MCA. These data suggest that GB34 acupuncture treatment improves the vasodilatory potential of the cerebral vasculature to compensate for fluctuations caused by changes in external conditions and could potentially be useful for the treatment of disorders of the ipsilateral MCA circulation.
Effect of acupuncture on the haemodynamic system in men
Authors: Okada Misaki , Taniguchi Hiroshi , Taniguchi Sazu , Kitakoji Hiroshi , Itoh Kazunori , Imai Kenji 
Published: March 2021

Background: Acupuncture stimulation decreases heart rate (HR) through somato-autonomic reflexes. However, the mechanisms responsible for other cardiovascular changes induced by acupuncture, such as its effects on stroke volume (SV) and blood pressure (BP), remain obscure. Objective: To evaluate continuously the comprehensive cardiovascular changes occurring during acupuncture. Method: 20 healthy men participated in the study. HR, SV and BP were measured in the supine position using electrocardiogram, transthoracic impedance cardiography and continuous non-invasive finger blood pressure, respectively. Manual acupuncture stimulation using a stainless steel needle was performed at LI10 for 60 s after resting periods of approximately 15 min. Results: HR was reduced and SV increased, in parallel, during the period of acupuncture stimulation (P<0.01, respectively). Diastolic blood pressure (DBP) decreased in the 10 s period of acupuncture stimulation compared with the 120 s pre-stimulation period (P<0.01) and recovered close to the pre-stimulation reading instantly after the transient reduction. No change was observed in cardiac output (CO) derived from HR and SV. Conclusions: This study indicates that HR reduction during acupuncture does occur, as previous reports have indicated. SV increased during acupuncture stimulation in parallel with HR reduction and CO was maintained during these changes. Any reduction in DBP caused by acupuncture recovered to baseline, likely due to baroreflexes.