Cold Compression Research Articles

Hydrogen and Silicon Effects on Hexagonal Close Packed Fe Alloys at High Pressures: Implications for the Composition of Earth's Inner Core

AbstractHexagonal close‐packed (hcp) structured Fe‐Ni alloy is believed to be the dominant phase in the Earth's inner core. This phase is expected to contain 4%–5% light elements, such as Si and H. While the effects of individual light element candidates on the equation of state (EoS) of the hcp Fe metal have been studied, their combined effects remain largely unexplored. In this study, we report the equations of state for two hcp‐structured Fe‐Si‐H alloys, namely Fe0.83Si0.17H0.07 and Fe0.83Si0.17H0.46, using synchrotron X‐ray diffraction measurements up to 125 GPa at 300 K. These alloys were synthesized by cold compression of Fe‐9wt%Si in either pure H2 or Ar‐H2 mixture medium in diamond‐anvil cells. The volume increase caused by a H atom in hcp Fe‐Si‐H alloys is approximately eight times greater than that by a Si atom. We used the improved data set to develop a composition‐dependent EoS that covers a wide range of compositions. Our calculated density and bulk sound velocity of hcp Fe‐Si‐H alloys suggest a large trade‐off between Si and H contents in fitting the seismic properties of the inner core. Combining our new EoS with geophysical and geochemical constraints, we propose 1.6–3 wt% Si and 0.15–0.6 wt% H in the Earth's inner core.

NURSING CARE FOR CLIENTS WHO EXPERIENCE POST OPERATING FEMUR FRACTURES WITH ACUTE PAIN NURSING PROBLEMS IN THE BIMA ROOM, JOMBANG HOSPITAL

Background:Fracture is a break or damage to the continuity of bone tissue caused by an external pressure that is greater than can be absorbed by the bone. Method:The research design was a case study using 2 postoperative femur fracture clients as subjects with acute pain nursing problems, nursing care was carried out for 3 consecutive days using cold compress therapy. Result:The results of the study showed acute pain by administering cold compress therapy, the problem was resolved by reducing pain scale to mild pain scale. Analysis:The results of the evaluation carried out by the researchers during the three days of treatment on both clients with postoperative femoral fracture problems found the diagnosis of acute pain was resolved. Conclusion:Non-pharmacological management of postoperative fracture patients with pain is to use cold compress therapy. Giving cold compresses can reduce pain, increase the release of endorphins which block the transmission of painful stimuli.

PENYULUHAN DAN DEMONTRASI KOMPRES DINGIN PADA PENDERITA FRAKTUR TERTUTUP DI POLI ORTHOPEDI RUMAH SAKIT UMUM KOTA LANGSA TAHUN 2022

One of the clinical manifestations felt by fracture patients is pain. Pain in fracture sufferers is sharp and stabbing, One way to reduce pain in fracture patients non-pharmacologically is to apply cold compresses to the pain area. Pain can occur in almost every fracture area, if not treated it can have a dangerous effect that will interfere with the healing process and increase morbidity and mortality. The purpose of the service is to increase the insight, knowledge and willingness of the community to apply cold compresses, especially to patients with closed fractures to reduce pain. Participants in this activity were 48 people with closed fractures at the Orthopedic Poly Hospital, Langsa City General Hospital. This community service method first carried out counseling, demonstration of cold compresses using an ice bottle. The results of community service showed that knowledge after being given counseling increased from 54.2% to 72.9% as well as the intensity of pain from moderate pain to mild pain the participants also said it was very comfortable to be given cold compresses. It is hoped that patients with closed fractures can do therapy non-pharmacological cold compresses to reduce pain and reduce the side effects of using drugs.

Effects of warm or cold compresses applied to the legs during hemodialysis on cramps, fatigue, and patient comfort: A placebo-controlled randomized trial.

Muscle cramps and fatigue are common complications in hemodialysis patients and have been associated with reduced patient comfort. Among the complementary therapies advocated for the management of these complications have been the application of warm or cold compresses to the extremities during a hemodialysis treatment. In this study, we compared the effects of warm or cold compresses application on cramping, fatigue, and patient comfort. This placebo-controlled randomized trial was done in 69 patients, who were stratified and randomly allocated to three treatment arms. Two of the three groups included an intervention; application of either warm (n=23) or cold (n=23) compresses to the extremities during dialysis. The third group served as a placebo control (n=23). The study period comprised 12 hemodialysis sessions. One week after the completion of the intervention, a follow-up dialysis session was also evaluated. Data were collected at baseline (t0 ), during each of 12 intervention sessions (t1 -t12 ), and at the follow-up session t13 . Cramps, fatigue, and patient comfort were evaluated using the Cramp Episode Follow-up Chart, Piper's Fatigue Scale, and the Hemodialysis Comfort Scale, respectively. In both the intervention and follow-up sessions, cramping and fatigue were lower, and comfort was higher in each of the intervention groups compared to placebo controls Application of warm compresses was superior to use of cold compresses. Both warm and cold compress administration reduced muscle cramps, fatigue, and hemodialysis comfort in hemodialysis patients.

Enhancing mechanical properties of friction stir welded AZ31 alloys by post-weld compression

In this work, the friction stir welded AZ31 joint was processed by a two-step post-weld deformation (i.e. compression at room temperature and an elevated temperature, respectively). The microstructure, texture and mechanical properties were systematically investigated. Profuse extension twins were observed after the first-step cold compression along normal direction, which largely affected the dynamic recrystallisation process during the second-step hot compression. Finally, the grain orientations and their convergence on the weld side were effectively altered, thereby contributing substantially to the enhancement of joint performance. Compared to the original joint, the yield strength, ultimate tensile strength and elongation were improved 64.7%, 20.8% and 52.5%, respectively. The underline strengthening mechanism was discussed by a comprehensive analysis of Schmid factor and geometric compatibility factor.

Enhanced recovery after surgery (ERAS) protocol in geriatric patients underwent unicompartmental knee arthroplasty: A retrospective cohort study.

The enhanced recovery after surgery (ERAS) pathway was formulated with the aim to reduce surgical stress response, alleviate pain and guarantee the best-fit experience of patients' perioperative period. However, the application of ERAS in geriatric patients who underwent unicompartmental knee arthroplasty (UKA) was relatively lacking. We hypothesize that UKA patients can benefit from the ERAS protocol. A total of 238 patients were recruited in this retrospective study from August 2018 to December 2021, and Oxford phase III UKA was applied to all patients. ERAS pathway included nutrition support, anesthesia mode, interoperative temperature, and blood pressure control, application of tranexamic acid, early initiation of oral intake and mobilization, and pain management. Demographic data, operation-relative variables, and postoperative complications were analyzed. Forgotten Joint Scores, Oxford Knee Score, Lysholm score, numerical rating scale, and knee range of motion were introduced to estimate the activity function and pain of surgical knee, and these variables were compared between the 2 groups. There were 117 patients in the ERAS group and 121 patients in the traditional group, respectively. The ERAS group had a shorter length of surgical incision and less intraoperative blood loss. Postoperative hemoglobin and albumin of patients in the ERAS group were better than those in the traditional group (P < .05), after 17.0 ± 10.8 months follow-up, the numerical rating scale, Lysholm, Oxford Knee Score, Forgotten Joint Scores, and knee range of motion of patients in the ERAS group were significantly better than the traditional group. The length of hospital stay for patients who underwent ERAS was 11.7 ± 3.8 days and the postoperative complication rate was lower for the ERAS group patients (P = .000 and 0.031). ERAS can reduce the length of hospital stay, and patients can achieve excellent postoperative knee function. The formulation and implementation of the ERAS protocol require good collaboration across multiple disciplines, as well as a deep understanding of the existing clinical evidence and the concept of the ERAS program.

Early warm compress treatment can promote recanalization of vascular embolisms and reduce tissue necrosis after polymethyl methacrylate injection

Injection of fillers for soft tissue augmentation can lead to a variety of complications, among which vascular occlusion caused by intravascular injection of filler will induce severe or permanent damage. The treatment strategies for intravascular embolization caused by injection include warm compress application, but the exact beneficial effects of this therapy have not been confirmed. The purpose of this study is to construct an intravascular injection embolism model and observe the effectiveness of warm and cold compress through a randomized, controlled trial. Thirty rabbit’s sixty ears were randomly divided into warm compress group, cold compress group, and control group. Polymethyl methacrylate (PMMA) was slowly injected into the central ear artery (CEA) to cause vascular embolism. Warm compress and cold compress treatment were performed respectively. The vascular recanalization and other related indexes were observed at 30 min, 1 day, and 7 days after injection, and the tissue necrosis was analyzed at 7 days. In the early stage of vascular embolization, warm compress can immediately promote vascular dilatation, blood circulation and partial blood flow recovery. One day after intravascular injection, warm compress can reduce intravascular embolization and reduce the incidence of tissue necrosis. At 7 days after intravascular injection, the vessels in the cold compress and control groups were still embolized while the percentage of recanalization in the warm compress group was 47.4% (P < 0.000). Early-stage warm compress after intravascular PMMA injection is conducive to recanalization of vascular embolization and reducing tissue necrosis.

Effect of cold application and compression on pain and bruising in subcutaneous heparin injection

Background and AimSubcutaneous administration may result in complications such as bruising and pain at the injection site. This study was performed as in order to determine the effect of cold application and compression on pain and bruising in subcutaneous heparin injection. MethodsThe study was a randomized controlled trial. 72 patients were included in the study. Each patient in the sample was both experimental (cold and compression) and control groups and 3 different parts of abdomen were used for injection of each patient. The data of the research were collected by using Patient Identification Form, Subcutaneous Heparin Observation Form and Visual Analog Scale (VAS). ResultsIn the study, it was observed that after heparin injection, ecchymosis developed in 16.4%, 28.8%, and 54.8% of the patients, respectively, and pain was experienced during injection in 12.3%, 43.5%, and 44.2% of the patients, respectively, on the pressure, cold application, and control site groups, and this difference was statistically significant (p<0.001). ConclusionIn the study, it was found that bruising size of the compression group was smaller in contrast with the other groups. When the VAS mean was examined for the groups, it was found that the patients in the compression group had lower pain than the other groups. In order to prevent complications that may arise in nurses' subcutaneous heparin injections and to increase the quality of patient care, it may be recommended to transfer the 60-second compression application after subcutaneous heparin applications to clinical applications and to conduct studies comparing compression and cold application with other applications for future studies.

Comparing the Effect of Local Application of Peppermint and Cold Compresses on the Severity of Pain from Venipuncture in Dialysis Patients: A Parallel Randomized Clinical Trial Study.

Pain at the injection site is one of the most common complaints in the clinic and is the most important symptom affecting the quality of life of hemodialysis (HD) patients. The aim of this study was to determine the effect and compare the topical application of peppermint and cold compresses on the intensity of pain caused by the insertion of a needle into the fistula of HD patients. In this parallel randomized clinical trial, 99 HD patients were assigned to three groups receiving peppermint, a cold compress, or a control using six blocks. For the peppermint group, 20 min before the needle's insertion, a peppermint gel was used; for the cold compress group, an ice pack was used; and for the control group, the usual method was applied. The patients' pain was assessed with the Visual Analog Scale immediately after the needle's insertion. The results showed that after the intervention, the mean and standard deviation of the pain score in the intervention groups receiving peppermint (4.81 ± 1.13) or a cold compress (4.78 ± 1.13) were significantly less than those of the control group (8.42 ± 1.22) (P <0.001), but there was no statistically significant difference between the peppermint group and the cold compress group (P = 0.91). The use of peppermint, which is a cheap and uncomplicated herbal medicine, and a cold compress, which is easy to use and available, is recommended to reduce the severity of pain caused by venipuncture in HD patients.

A Phase 3b Study for Management of Ocular Side Effects in Patients with Epidermal Growth Factor Receptor-Amplified Glioblastoma Receiving Depatuxizumab Mafodotin

Introduction: The Understanding New Interventions with GBM ThErapy (UNITE) study was designed to assess the effect of prophylaxis for ocular side effects (OSEs) in patients with glioblastoma receiving the antibody-drug conjugate (ADC) depatuxizumab mafodotin. UNITE (NCT03419403) was a phase 3b, open-label, randomized, exploratory study performed at 18 research sites in 5 countries. Methods: The study enrolled adult patients with epidermal growth factor receptor-amplified, histologically confirmed, newly diagnosed supratentorial glioblastoma or grade IV gliosarcoma, and a Karnofsky Performance Status ≥70, receiving depatuxizumab mafodotin. All patients were administered depatuxizumab mafodotin during concurrent radiotherapy and temozolomide and with adjuvant temozolomide. Ninety patients were to be randomized (1:1:1) to OSE prophylactic treatments with each depatuxizumab mafodotin infusion: (a) standard steroid eye drops, (b) standard steroid eye drops plus vasoconstrictor eye drops and cold compress, or (c) enhanced steroids plus vasoconstrictor eye drops and cold compress. A Corneal Epitheliopathy Adverse Event (CEAE) scale was devised to capture symptoms, grade OSEs (scale of 0–5), and inform ADC dose modifications. The primary endpoint was the frequency of a required change in OSE management due to inadequate control of OSEs, defined as decline from baseline in visual acuity (using logarithm of the minimum angle of resolution [LogMAR] scale) or a Grade ≥3 CEAE event, in the worst eye in the first 8 weeks of treatment; unless otherwise specified, the treatment period refers to both the chemoradiation and adjuvant phases. Results: The UNITE study was stopped early after interim analysis of separate phase III trial showed no difference in survival from depatuxizumab mafodotin. Forty patients were randomized (38 received depatuxizumab mafodotin). Overall, 23 patients experienced inadequate control of OSEs that required change in OSE management within 8 weeks of treatment, with 21 (70.0%) experiencing ≥+0.3 change on LogMAR scale in baseline-adjusted visual acuity and 12 reporting a grade ≥3 CEAE. There were no definitive differences among prophylactic treatments. Conclusions: The premature cessation of the study precludes definitive conclusions regarding the OSE prophylaxis strategies. No new clinically significant safety findings were noted. Despite these limitations, this study highlights the need for novel assessment tools to better understand and mitigate OSEs associated with ADCs.

Acute phase of epidemic keratoconjunctivitis: Management in practice

AbstractPurpose: To describe current trends in therapeutic modalities to manage acute epidemic keratoconjunctivitis.Methods: We ran a descriptive study of 87 eyes of 61 patients diagnosed with acute epidemic keratoconjunctivitis confirmed by the presence of subepithelial infiltrates (SEIs) in the cornea. A clinical score based on a complete biomicroscopic examination, the measurement of visual acuity, the number of subepithelial infiltrates (SEIs), the break‐up‐time, and the value of the Schirmer type 1, has been established to evaluate symptoms.Results: The mean age of the study population was 36 ± 17 years‐old. The treatments taken in the acute phase were either prescribed by a general practitioner (10%) or an ophthalmologist (60%), or taken as self‐medication (30%). None of our patients has received nonsteroidal anti‐inflammatory eye drops. Antivirals including ganciclovir were taken by 40% of the study group, artificial tears in 81 eyes (93%), antiseptics in 21% of the cases, and local antibiotics in 46 eyes (53%). The mean clinical score was 4.2 ± 2.6. There was no significant difference in the final clinical score, visual acuity, number of SEIs, break‐up time and Schirmer's value between the groups who instilled ganciclovir, artificial tears, local antibiotics as well as the healing agents and those who did not. Visual acuity was better in patients who did not use antiseptic eye drops.Conclusions: The latest treatment recommended for the acute phase of epidemic keratoconjunctivitis are artificial tears with cold compresses, local povidone‐iodine and ganciclovir. Topical antibiotics are only used in confirmed bacterial superinfection. Our studied sample did not respond much to these recommendations.

PSAT186 Iatrogenic Calcinosis Cutis in a Patient With Postsurgical Hypoparathyroidism

Abstract Clinical Case A 44-year old woman, diagnosed with post-surgical hypoparathyroidism after total thyroidectomy for papillary thyroid carcinoma, was admitted for symptomatic hypocalcemia. On admission, she had positive Trousseau's and Chvostek's signs, carpopedal spasm and prolonged QT interval on ECG. She had an initial serum ionized calcium of 0.70 mmol/L (RI: 1.09- 1.30). Serum phosphorus was also elevated at 5.8 mg/dL (RI: 2.6-4.7). She was given 2 grams of calcium gluconate via slow IV push and was hooked to calcium gluconate drip, 4 grams in 250 cc D5W to run for 8 hours In less than 24 hours, she developed thrombophlebitis on her right hand, hence the drip was shifted to the left hand. The new IV site also developed phlebitis, necessitating transfer to the right antecubital area. The areas of phlebitis were managed with cold compress, pain relievers, topical antibiotics overlapped with oral antibiotics. She continued receiving calcium gluconate IV drips overlapped with calcium and calcitriol tablets until her serum calcium level normalized. She was discharged stable and improved after 4 days but still with erythema over her previous IV sites. However, 3 weeks after discharge, she developed yellowish erythematous plaques and nodules over her previous IV sites. She consulted with a dermatologist who did a skin punch biopsy showing a granulomatous dermatitis, foreign body type, which confirmed the diagnosis of iatrogenic calcinosis cutis. She was treated with pulse dye laser and intra-lesional triamcinolone, oral antibiotics and pain medications. At present, she still has pain, tenderness, with limitation of movement on both hands. She was referred to a plastic surgeon where she was advised to undergo a total of 3 surgeries over a span of 3-6 months. These would involve the placement of tissue expanders, harvesting of flaps, removal of lesions and reconstruction of scars plus hand rehabilitation after the surgeries. Conclusion Iatrogenic calcinosis cutis is a rare complication from extravasation of calcium-containing solutions during intravenous calcium correction. It appears 2-3 weeks after extravasation and has no definitive treatment. In other case reports, it can be managed conservatively but some may require reconstructive surgery. Prevention of extravasation is the only way to avoid this rare and debilitating condition.Reference: Jiménez-Gallo D, Ossorio-García L, Linares-Barrios M. Calcinosis Cutis and Calciphylaxis. Actas Dermosifiliogr. 2015 Dec;106(10): 785-94. Presentation: Saturday, June 11, 2022 1:00 p.m. - 3:00 p.m.

PENERAPAN KOMPRES DINGIN (ICE GEL) TERHADAP PENURUNAN NYERI LUKA EPISIOTOMI PADA PASIEN POST PARTUM DI RSUD Dr. SOESELO KABUPATEN TEGAL

This study aims to determine the application of cold compress (ice gel) to reduce episiotomy wound pain in post partum patients at RSUD Dr. Soeselo Tegal Regency. This research method is a descriptive method with the research design being a case study. The results of the case study study with cold compress therapy (ice gel) had a significant influence in reducing the scale of pain in post partum patients with episiotomy wound pain. There was a decrease in the pain scale of the two respondents, namely the level of the pain scale before being given cold compress therapy (ice gel) in patient 1 pain scale 6 and patient 2 pain scale 7, after being given cold compress therapy (ice gel) for 3 days to both patients the pain scale dropped to 2. The application of cold compress (ice gel) is recommended to be done 3 times a day for 3 days with a duration of 5-10 minutes at a temperature of 15o C to reduce pain. In conclusion, cold compress therapy (ice gel) can reduce episiotomy wound pain in post partum patients.Keywords : Pain, Episiotomy, Cold Compress.

Comparison of Microbial Sampling Sites and Donor-Related Factors on Corneal Graft Contamination.

Grafts used for corneal donation should be sterile to avoid transplantation failure and secondary infection. However, there are no clear and globally accepted specifications from eye banks on microbial sampling sites. The objective of this study was to analyze microbial contamination of corneal grafts collected from different sampling sites. We found that the contamination rates and strain compositions significantly differed at different sampling sites. To clarify the effect of the microbial sampling site on corneal graft contamination, microbial sampling was conducted using 30 corneal grafts at the extraocular and intraocular sides of the graft in 2020 from the National Eye Bank of Taiwan. Microbial contamination significantly differed (p &lt; 0.05) between the different sampling sites on the graft according to McNemar's test. Although the two sampling sites showed the same specificity (33.33%), the sensitivity of sampling on the extraocular side (82.35%) was higher than that on the intraocular side (17.65%) of the graft. Donor-associated factors, including the cause of death, operating place, and cold compression, were analyzed using chi-square statistics, which revealed no significant differences in microbial contamination. Thus, our data provide evidence for the microbial sampling site of donated grafts and clear specifications for maintaining the quality of corneal grafts.

Comparative Effects of Dynamic Stretching and Ice Bag Application On the Physical Performance in Recreational Basketball Players: A Randomized Crossover Study

Introduction: Researchers found that cryotherapy at the ankle joint heightened adjacent muscle activity and reflex amplitude, which facilitated greater force production at the ankle complex. Furthermore, cryotherapy appears to increase musculoarticular stiffness, which has been associated with heightened muscular performance at a joint. Aim and objective: the aim of the study is to examine the influence of dynamic stretching and IBA technique on the physical performance. Methodology: Total 20 healthy male basketball athletes encompassing two groups participated in the current study. The study consisted of two groups, Group A (ice bag application) and Group B (dynamic stretching). Cold compress was applied over the anterior thigh, posterior thigh, and calf. Subjects were assigned to Group A, and Group B, using Convenience sampling method. Each candidate performed the 5 minutes of jogging before taking intervention. All subjects performed three functional performance tests: Vertical Jump Test, Agility T-test &amp; 20-meter sprint. Each participant attended an orientation session to become familiar with the testing procedures. Subjects were randomly assigned into two groups and exposed to a crossover study design. The experiment was performed on two separate occasions whereby one group received the dynamic stretching in the first session, while the other group uses the cryotherapy first. After 48 hours, (cooling session) on the next occasion, the groups were changed and the second group receives the cryotherapy, while the first group performs dynamic stretching. On both occasions, the dynamic stretching and cryotherapy interventions were the same. Between the sessions, the subjects will not allow to participate in any kind of vigorous physical activity. Results: The present study showed an increase in performance of recreational Basketball players by the combination of 5 minutes of warm up plus 6 min of dynamic stretching on the vertical jump height and 20-meter sprint.

OA32 Minimally invasive, ultrasound-guided tissue biopsies of synovial tissue in children with Juvenile Idiopathic Arthritis for research: a feasibility study

Introduction/BackgroundWhen investigating disease mechanisms, site-specific differences in immune cell phenotype and function have highlighted the need to analyse cellular and molecular mechanisms at the tissue site directly. In adults, the ability to obtain synovial tissue biopsies using ultrasound-guided techniques, combined with advanced tissue analytics, has revolutionised our understanding of the cellular ecosystem that operates within the joint and how it contributes to disease. However, a similar approach in paediatric disease is lacking. Description/MethodAims: 1) To describe the protocol for undertaking minimally invasive ultrasound-guided synovial tissue biopsies in children and young people with arthritis, for the purpose of research, alongside routine clinical care. 2) To investigate whether high-quality synovial tissue can be obtained that is suitable for downstream applications including single cell profiling technologies, histology and digital spatial profiling.Treatment-naïve children with a diagnosis of Juvenile Idiopathic Arthritis, who were being referred for a corticosteroid joint injection were recruited from two large UK Paediatric Rheumatology centres. We established a workflow pipeline for performing synovial tissue biopsies in child and young people with arthritis, using standardised procedures for biopsy and sample processing. Procedures were performed by experienced paediatric interventional radiologists with experience of joint biopsy for diagnostic purposes. Following a general anaesthetic, required as part of routine clinical care and the establishment of sterility, synovial fluid was aspirated. Needle-biopsies were undertaken from the same needle insertion site and subsequently corticosteroid was injected into the joint. Thickened synovium was graded via ultrasonography. Participating families completed questionnaires prior to and following synovial biopsy.Discussion/Results11 participants were recruited to the study over a nine month period, with a median age of 7 years (range 1-16 years); 91% were female. Samples obtained included core synovial biopsies, paired synovial fluid and peripheral blood. Synovial tissue fragments were processed for histology by formalin fixation and cryopreserved for downstream applications, including RNA sequencing and cell culture. Quality control indices included histological analysis to ensure the biopsied material was characteristically synovium and to grade the severity of inflammation. No significant complications were reported; however, one child had a mild haemarthrosis controlled with cold saline wash out and cold compresses.Key learning points/ConclusionObtaining biopsies of synovial tissue in children with Juvenile Idiopathic Arthritis for the purpose of research, alongside clinical care is feasible. Analysis of tissue direct from the site of inflammation with single-cell RNA sequencing in children is achievable.

Microstructure evolution and shear band formation in an ultrafine-grained Ti–6Al–4V alloy during cold compression

It is generally accepted that dynamic recrystallization (DRX) is the result of shear banding in metallic materials. However, we observed the microstructure evolution in an ultrafine-grained Ti–6Al–4V alloy under quasi-static compression and found the formation of DRX induced micro shear bands at the initial stage of plastic deformation. It is of interest that the strain-localized regions experienced a two-step recrystallization process, thus resulting in the formation of refined dynamic recrystallized (DRX) grains in transition zones and nanograins in core regions of micro shear bands successively. It is suggested that the DRX taking place at local regions led to the strain softening, which subsequently accelerated the formation of micro shear bands. Micro shear bands nucleated, grew wider, multiplied and propagated by means of gradually consuming the DRX regions with the increase of local strains. Those micro shear bands are considered to contribute to synergetic plastic deformation in addition to dislocation slipping at lower strains, while some macro shear bands are regarded as the precursor of fracture at higher strains. Based on the observation results a new DRX mechanism of shear band was proposed. The experimental results in the present work can provide new evidences and novel insights of the shear-band formation, plastic deformation as well as failure mode in UFG alloys under quasi-static loading conditions.

Perineal Massage for Prevention of Perineal Trauma and Episiotomy During Labor: A Systematic Review and Meta-Analysis.

Objective: Vaginal births are associated with a certain degree of trauma to the genital tract, with significant short-term and long-term morbidity. Awareness of morbidity following perineal trauma has led to application of different interventions during the late first stage and second stage of labour to prevent severe perineal trauma. This includes techniques such as perineal massage, warm and cold compresses, and perineal management techniques. Objective of this meta-analysis is to evaluate the effect of perineal massage during the late first stage and second stage of labour on the rate of episiotomy and risk of perineal trauma. Materials and methods: Electronic databases (PubMed, Scopus, Cochrane Library and Science Direct) were searched from inception until August 2021. We included randomized controlled trials (RCTs) which compares perineal massage during labor (i.e., intervention group) with a control group in women with singleton gestation and cephalic presentation at ≥36 weeks. The primary outcome was severe perineal trauma and the rate of episiotomy. Meta-analysis was performed using the random-effects model of DerSimonian and Laird to produce summary treatment effects in terms of relative risk (RR) with 95% confidence interval (CI). Results: Ten trials including 4,088 women were analyzed. Women with perineal massage during labor had a significantly lower incidence of severe perineal trauma (RR: 0.52, 95% CI 0.29- 0.94) compared to the control group. The incidence of episiotomy was lower in the perineal massage group (RR: 0.71, 95% CI 0.52-0.98 p < 0.01) but was statistically insignificant (P>0.05). Conclusion: The finding of meta-analysis showed that perineal massage during labor could be effective in reducing the risk of severe perineal trauma, such as third- and fourth-degree spontaneous lacerations during labor.

Synthesis of an Aluminum Alloy Metal Matrix Composite Using Powder Metallurgy: Role of Sintering Parameters

Powder metallurgy-based metal matrix composites (MMCs) are widely chosen and used for the development of components in the fields spanning aerospace, automotive and even electronic components. Engineered MMCs are known to offer a high strength-to-weight (σ/ρ) ratio. In this research study, we synthesized cylindrical sintered samples of a ceramic particle-reinforced aluminum metal matrix using the technique of powder metallurgy. The samples for the purpose of testing, examination and analysis were made by mixing aluminum powder with powders of silicon carbide and aluminum oxide or alumina. Four varieties of aluminum composite were synthesized for a different volume percent of the ceramic particle reinforcement. The hybrid composite contained 2 vol.% and 7 vol.% of silicon carbide and 3 vol.% and 8 vol.% of alumina with aluminum as the chosen metal matrix. Homogeneous mixtures of the chosen powders were prepared using conventional ball milling. The homogeneous powder mixture was then cold compacted and subsequently sintered in a tubular furnace in an atmosphere of argon gas. Five different sintering conditions (combinations of temperature and sintering time) were chosen for the purpose of this study. The density and hardness of each sintered specimen were carefully evaluated. Cold compression tests were carried out for the purpose of determining the compressive strength of the engineered MMC. The sintered density and hardness of the aluminum MMCs varied with the addition of ceramic particle reinforcements. An increase in the volume fraction of the alumina particles to the Al/SiC mixture reduced the density, hardness and compressive strength. The sintering condition was optimized for the aluminum MMCs based on the hardness, densification parameter and cold compressive strength. The proposed powder metallurgy-based route for the fabrication of the aluminum matrix composite revealed a noticeable improvement in the physical and mechanical properties when compared one-on-one with commercially pure aluminum.

Effect of pressure quenching on the structures and properties of borosilicate glasses: Insights from molecular dynamics simulations

Combining thermal and pressure effect represents a novel approach to modify glass properties. However, the microscopic structural origin of these property modifications is complex and far from fully understood, especially in multicomponent glasses with mixed glass formers. In this paper, we have utilized classical molecular dynamics simulations with a set of composition dependent potentials to investigate pressure-quenching effect on sodium borosilicate glasses. Processes including hot compression, cold compression and subsequent annealing on the structures and properties are investigated and compared. It was found that applying pressure up to 10 GPa at the glass transition temperature led to permanent densifications and a dramatic increase of elastic moduli by 90%, while thermal annealing reversed the increase and applying pressure at ambient temperture did not increase the modulus. The main structural change of the hot compressed sample is the increase of four-fold coordinated boron while silicon remains four-fold coordinated. The sodium environment shows an increase of coordination number and a decrease of Na O and Na Na bond distances. Medium range structure is also changed with an increase of 8-membered rings. These results provide atomistic insights of the pressure quench effect on borosilicate glasses. • Compared cold compression, compression near T g and annealing effect on glass structure and properties • Up to 90% increase of elastic moduli due to hot compression while cold compression led to little change of elastic properties • Hot compression increases [4] B and Na coordination while a decrease of Na O bond distance • Medium range structure change observed in ring size distribution • Combing thermal and pressure effect a novel way to modify glass properties