Studies of minority carrier diffusion length increase in p-type ZnO : Sb

Minority electron diffusion length was measured in p-type, Sb-doped ZnO as a function of temperature using the electron beam induced current technique. A thermally induced increase of electron diffusion length was determined to have an activation energy of 184 +/- 10 meV. Irradiation with a low energy (5 kV) electron beam also resulted in an increase of diffusion length with a similar activation energy (219 +/- 8 meV). Both phenomena are suggested to involve a Sb-Zn-2V(Zn) acceptor complex. Saturation and relaxation dynamics of minority carrier diffusion length are explored. Details of a possible mechanism for diffusion length increase are presented

Electron beam induced current profiling of ZnO p-n homojunctions

Variable temperature electron beam induced current technique was employed for the profiling of ZnO p-n homojunctions and the extraction of minority electron diffusion length values in the Sb-doped p-type ZnO region. A thermally induced increase for diffusion length of minority electrons was determined to have an activation energy of similar to 145 meV. The latter parameter likely represents carrier delocalization energy and determines the increase of the diffusion length due to the reduction in recombination efficiency. (c) 2008 American Institute of Physics

All-arthroscopic versus mini-open repair of small or moderate-sized rotator cuff tears: A protocol for a randomized trial [NCT00128076]

BACKGROUND: Rotator cuff tears are the most common source of shoulder pain and disability. Only poor quality studies have compared mini-open to arthroscopic repair, leaving surgeons with inadequate evidence to support optimal, minimally-invasive repair. METHODS/DESIGN: This randomized, multi-centre, national trial will determine whether an arthroscopic or mini-open repair provides better quality of life for patients with small or moderate-sized rotator cuff tears. A national consensus meeting of investigators in the Joint Orthopaedic Initiative for National Trials of the Shoulder (JOINTS Canada) identified this question as the top priority for shoulder surgeons across Canada. The primary outcome measure is a valid quality-of-life scale (Western Ontario Rotator Cuff (WORC)) that addresses 5 domains of health affected by rotator cuff disease. Secondary outcomes will assess rotator cuff functionality (ROM, strength, Constant score), secondary dimensions of health (general health status (SF-12) and work limitations), and repair integrity (MRI). Outcomes are measured at baseline, at 6 weeks, 3, 6, 12, and 24 months post-operatively by blinded research assistants and musculoskeletal radiologists. Patients (n = 250) with small or medium-sized cuff tears identified by clinical examination and MRI who meet eligibility criteria will be recruited. This sample size will provide 80% power to statistically detect a clinically important difference of 20% in WORC scores between procedures after controlling for baseline WORC score (α = 0.05). A central methods centre will manage randomization, data management, and monitoring under supervision of experienced epidemiologists. Surgeons will participate in either conventional or expertise-based designs according to defined criteria to avoid biases from differential surgeon expertise. Mini-open or all-arthroscopic repair procedures will be performed according to a standardized protocol. Central Adjudication (of cases), Trial Oversight and Safety Committees will monitor trial conduct. We will use an analysis of covariance (ANCOVA), where the baseline WORC score is used as a covariate, to compare the quality of life (WORC score) at 2 years post-operatively. As a secondary analysis, we will conduct the same statistical test but will include age and tear size as covariates with the baseline score. Enrollment will require 2 years and follow-up an additional 2 years. The trial will commence when funding is in place. DISCUSSION: These results will have immediate impact on the practice behaviors of practicing surgeons and surgical trainees at JOINTS centres across Canada. JOINTS Canada is actively engaged in knowledge exchange and will publish and present findings internationally to facilitate wider application. This trial will establish definitive evidence on this question at an international level

ВОЗМОЖНОСТИ ОЦЕНИВАНИЯ БАССЕЙНОВОЙ ТРАНСПИРАЦИИ НА ОСНОВЕ ИЗМЕРЕНИЯ СТВОЛОВОГО СОКОДВИЖЕНИЯ: ПОСТАНОВКА ЗАДАЧИ

Study of seasonal dynamics and evapotranspiration volume of forested catchments (mainly forest stand transpiration) is the relevant objective for fundamental knowledge and practical applications. However, there are many difficulties: labor efforts of direct observations, many factors affecting against each other, observational data scaling and so on. As a result, evapotranspiration during hydrological modeling is determined by the leftover principle and simplified techniques, leading to wrong representation of water balance structure. The presented article deals with the first results of our research group focused on setting up field measurements of xylem sap flow using trunk sap flow measuring sensors as well as development of sap flow assessment methods for individual trees and whole catchment. The investigations were performed for mixed coniferous-broad leaved forests at the territory of the Central Sikhote-Alin’ within Verkhneussuriyskiy biogeocenotical station of FSC of the East Asia Terrestrial Biodiversity FEB RAS. This site is used for water balance measuring surveys from 2011. Sap flow was measured continuously during June-October of 2019 on one of the local dominant tree species. Apparently, such investigations are novel for the Russian Far East region. It is expected that direct sap flow measurements for individual trees refinement methods, data scaling and its integration to the hydrometeorological observations will help to make a comprehensive analysis of catchments water balance and to integrate measured data into hydrological models.Изучение сезонной динамики и объемов суммарного испарения лесных водосборов (главным образом транспирации древостоев) является актуальнейшей задачей как в фундаментальном, так и прикладном аспектах. Ее решение связано с рядом сложностей: трудоемкость прямого наблюдения, наличие большого количества влияющих друг на друга факторов, необходимость распространения данных точечных измерений на площадь и многие другие. Это приводит к тому, что при моделировании водного баланса речных бассейнов испарение определяется по упрощенным схемам, остаточному принципу, что ведет к неправильному отражению структуры водного баланса. Настоящая статья представляет первые результаты усилий инициативного коллектива исследователей, направленных на постановку экспериментальных измерений ксилемного потока с использованием современных датчиков стволового сокодвижения, а также развития методов оценки транспирации как отдельных деревьев, так и бассейновой транспирации на основе этих данных. Исследование проведено на территории смешанных хвойно-широколиственных лесов Центрального Сихотэ-Алиня в пределах экспериментального водосбора, входящего в состав Верхнеуссурийского биогеоценотического стационара ФНЦ Биоразнообразия ДВО РАН, на котором рабочей группой возобновлены воднобалансовые работы в 2011 г. и в настоящее время являются уже постоянными. Регистрация стволового сокодвижения выполнялась в период с июня по начало октября 2019 года на одном из доминантных видов местного растительного сообщества. В Дальневосточном регионе России работы такого плана, по-видимому, проведены впервые. Предполагается, что отработка методов оценки прямых измерений транспирации на уровне отдельных деревьев, попытка пространственной генерализации на территорию топологического масштаба и вовлечение полученной информации в комплекс гидрометеорологических наблюдений позволят выполнить исчерпывающий анализ водного баланса в пределах малого речного бассейна и интегрировать поток измеряемых данных по испарению в гидрологические модели. &nbsp

The results of arthroscopic anterior stabilisation of the shoulder using the bioknotless anchor system

<p>Abstract</p> <p>Background</p> <p>Shoulder instability is a common condition, particularly affecting a young, active population. Open capsulolabral repair is effective in the majority of cases, however arthroscopic techniques, particularly using suture anchors, are being used with increasing success.</p> <p>Methods</p> <p>15 patients with shoulder instability were operated on by a single surgeon (VK) using BioKnotless anchors (DePuy Mitek, Raynham, MA). The average length of follow-up was 21 months (17 to 31) with none lost to follow-up. Constant scores in both arms, patient satisfaction, activity levels and recurrence of instability was recorded.</p> <p>Results</p> <p>80% of patients were satisfied with their surgery. 1 patient suffered a further dislocation and another had recurrent symptomatic instability. The average constant score returned to 84% of that measured in the opposite (unaffected) shoulder. There were no specific post-operative complications encountered.</p> <p>Conclusion</p> <p>In terms of recurrence of symptoms, our results show success rates comparable to other methods of shoulder stabilisation. This technique is safe and surgeons familiar with shoulder arthroscopy will not encounter a steep learning curve. Shoulder function at approximately 2 years post repair was good or excellent in the majority of patients and it was observed that patient satisfaction was correlated more with return to usual activities than recurrence of symptoms.</p

Posterior shoulder tightness; an intersession reliability study of 3 clinical tests.

Background Although posterior shoulder tightness (PST) has been associated with shoulder pathology and altered glenohumeral joint kinematics, uncertainty remains regarding its cause and definition. To understand the efficacy of treatments for PST, it must be possible to identify people with PST for the purposes of research and clinical decision-making. Clinical tests for PST must demonstrate acceptable levels of measurement reliability in order to identify the condition and to evaluate the response to intervention. There is currently a lack of research describing intersession reliability for measures of PST. The aim of this study was to quantify the inter-session reliability for three clinical tests used to identify PST over a 6–10 week interval. Methods A convenience sample of 26 asymptomatic adult participants (52 shoulders) were recruited from a university setting over a five-month duration. Participants attended the human movement laboratory for measurement of glenohumeral joint internal rotation, horizontal adduction and low flexion on two occasions separated by an interval of 6–10 weeks. Intra-class correlation coefficients were calculated from the mean square values derived from the within-subject, single factor (repeated measures) ANOVA. Test-retest measurement stability was evaluated by calculating the standard error of measurement and the minimum detectable change for each measurement. Results All 3 tests demonstrated good intersession intra-rater reliability (0.86–0.88), and the standard error of measurement (95%) were 7.3° for glenohumeral horizontal adduction, 9.4° for internal rotation, and 6.9° for low flexion. The minimum detectable change for glenohumeral horizontal adduction was 10.2°, internal rotation was 13.3°, and low flexion was 9.7°. Conclusion In this population of people without symptoms, the 3 measures of PST all demonstrated acceptable inter-session reliability. The standard error of measurement and minimum detectable change results can be used to determine if a change in measures of PST are due to measurement error or an actual change over time.Peer reviewe

Post-traumatic glenohumeral cartilage lesions: a systematic review

<p>Abstract</p> <p>Background</p> <p>Any cartilage damage to the glenohumeral joint should be avoided, as these damages may result in osteoarthritis of the shoulder. To understand the pathomechanism leading to shoulder cartilage damage, we conducted a systematic review on the subject of articular cartilage lesions caused by traumas where non impression fracture of the subchondral bone is present.</p> <p>Methods</p> <p>PubMed (MEDLINE), ScienceDirect (EMBASE, BIOBASE, BIOSIS Previews) and the COCHRANE database of systematic reviews were systematically scanned using a defined search strategy to identify relevant articles in this field of research. First selection was done based on abstracts according to specific criteria, where the methodological quality in selected full text articles was assessed by two reviewers. Agreement between raters was investigated using percentage agreement and Cohen's Kappa statistic. The traumatic events were divided into two categories: 1) acute trauma which refers to any single impact situation which directly damages the articular cartilage, and 2) chronic trauma which means cartilage lesions due to overuse or disuse of the shoulder joint.</p> <p>Results</p> <p>The agreement on data quality between the two reviewers was 93% with a Kappa value of 0.79 indicating an agreement considered to be 'substantial'. It was found that acute trauma on the shoulder causes humeral articular cartilage to disrupt from the underlying bone. The pathomechanism is said to be due to compression or shearing, which can be caused by a sudden subluxation or dislocation. However, such impact lesions are rarely reported. In the case of chronic trauma glenohumeral cartilage degeneration is a result of overuse and is associated to other shoulder joint pathologies. In these latter cases it is the rotator cuff which is injured first. This can result in instability and consequent impingement which may progress to glenohumeral cartilage damage.</p> <p>Conclusion</p> <p>The great majority of glenohumeral cartilage lesions without any bony lesions are the results of overuse. Glenohumeral cartilage lesions with an intact subchondral bone and caused by an acute trauma are either rare or overlooked. And at increased risk for such cartilage lesions are active sportsmen with high shoulder demand or athletes prone to shoulder injury.</p

Effectiveness of individualized physiotherapy on pain and functioning compared to a standard exercise protocol in patients presenting with clinical signs of subacromial impingement syndrome. A randomized controlled trial

<p>Abstract</p> <p>Background</p> <p>Shoulder impingement syndrome is a common musculoskeletal complaint leading to significant reduction of health and disability. Physiotherapy is often the first choice of treatment although its effectiveness is still under debate. Systematic reviews in this field highlight the need for more high quality trials to investigate the effectiveness of physiotherapy interventions in patients with subacromial impingement syndrome.</p> <p>Methods/Design</p> <p>This randomized controlled trial will investigate the effectiveness of individualized physiotherapy in patients presenting with clinical signs and symptoms of subacromial impingement, involving 90 participants aged 18-75. Participants are recruited from outpatient physiotherapy clinics, general practitioners, and orthopaedic surgeons in Germany. Eligible participants will be randomly allocated to either individualized physiotherapy or to a standard exercise protocol using central randomization.</p> <p>The control group will perform the standard exercise protocol aiming to restore muscular deficits in strength, mobility, and coordination of the rotator cuff and the shoulder girdle muscles to unload the subacromial space during active movements. Participants of the intervention group will perform the standard exercise protocol as a home program, and will additionally be treated with individualized physiotherapy based on clinical examination results, and guided by a decision tree. After the intervention phase both groups will continue their home program for another 7 weeks.</p> <p>Outcome will be measured at 5 weeks and at 3 and 12 months after inclusion using the shoulder pain and disability index and patients' global impression of change, the generic patient-specific scale, the average weekly pain score, and patient satisfaction with treatment. Additionally, the fear avoidance beliefs questionnaire, the pain catastrophizing scale, and patients' expectancies of treatment effect are assessed. Participants' adherence to the protocol, use of additional treatments for the shoulder, direct and indirect costs, and sick leave due to shoulder complaints will be recorded in a shoulder log-book.</p> <p>Discussion</p> <p>To our knowledge this is the first trial comparing individualized physiotherapy based on a defined decision making process to a standardized exercise protocol. Using high-quality methodologies, this trial will add evidence to the limited body of knowledge about the effect of physiotherapy in patients with SIS.</p> <p>Trial registration</p> <p>Current Controlled Trials ISRCTN86900354</p