How pinning and contact angle hysteresis govern quasi-static liquid drop transfer.

This paper presents both experimental and numerical simulations of liquid transfer between two solid surfaces with contact angle hysteresis (CAH). Systematic studies on the role of the advancing contact angle (θa), receding contact angle (θr) and CAH in determining the transfer ratio (volume of the liquid transferred onto the acceptor surface over the total liquid volume) and the maximum adhesion force (Fmax) were performed. The transfer ratio was found to be governed by contact line pinning at the end of the transfer process caused by CAH of surfaces. A map based on θr of the two surfaces was generated to identify the three regimes for liquid transfer: (I) contact line pinning occurs only on the donor surface, (II) contact line pinning occurs on both surfaces, and (III) contact line pinning occurs only on the acceptor surface. With this map, an empirical equation is provided which is able to estimate the transfer ratio by only knowing θr of the two surfaces. The value of Fmax is found to be strongly influenced by the contact line pinning in the early stretching stage. For symmetric liquid bridges between two identical surfaces, Fmax may be determined only by θa, only by θr, or by both θa and θr, depending on the magnitude of the contact angles. For asymmetric bridges, Fmax is found to be affected by the period when contact lines are pinned on both surfaces.

The relationships of change in work climate with changes in burnout and depression: a 2-year longitudinal study of Chinese mental health care workers.

Mental health care workers face heavy emotional demand and are prone to work burnout. Work burnout has been associated with poor mental health and work climate, which refers to individual perceptions about work setting. The purpose of this study was to examine whether intra-individual changes in work climate were associated with intra-individual changes in burnout and depression over two years. The present sample included Chinese mental health care workers (N = 312; mean age = 38.6, SD = 9.9) working in a psychosocial rehabilitation institution. The participants completed questionnaires on work climate, work burnout and depression at seven time points across two years. Parallel process latent growth modeling was used to analyze the associations of change between work climate and burnout and depression. Work climate displayed a logarithmic decreasing trend while burnout and depression displayed logarithmic increasing trends over two years. Baseline levels of work climate were negatively and moderately associated with baseline levels of burnout and depression (r = -.44 to -.60, p < .01). Changes in work climate were negatively and moderately associated with change in burnout (r = -.43, p < .01) and change in depression (r = -.31, p < .05). Change in burnout was positively and strongly associated (r = .58, p < .01) with change in depression. The current results support temporal relationships among changes in work climate, burnout and depression across time. Practical implications for future preventive work in burnout interventions were discussed within this population.

Coracoclavicular ligament reconstruction using a gracilis tendon graft for acute type-III acromioclavicular dislocation.

PURPOSE: To review the functional and radiological results of patients after coracoclavicular ligament reconstruction. METHODS: Five patients aged 21 to 50 (mean, 37) years with acute Rockwood type-III acromioclavicular dislocation underwent coracoclavicular ligament reconstruction with autogenous gracilis tendon grafts. Patients were either active in sports or heavy manual workers. Assessments on shoulder function (using the Constant score), wound size, pain (using a visual analogue scale), and reduction (using radiographs of both acromioclavicular joints) were made. RESULTS: The mean follow-up period was 26 (range, 15-43) months; the mean time to return to work or sports was 14 (range, 12-20) weeks. The mean Constant score was 94 (range, 90-98). The mean donor-site scar size was 3 cm and the mean pain score was 0. No major complication or donor-site morbidity was noted. There was one subluxation. CONCLUSION: Coracoclavicular ligament reconstruction using an autogenous gracilis tendon graft was safe in physically active patients having acute type-III acromioclavicular dislocation.

Pseudoaneurysm of the geniculate artery following total knee arthroplasty: a report of two cases.

We report 2 cases of pseudoaneurysm of the geniculate artery after a total knee arthroplasty (TKA). The first one was located in the superomedial geniculate artery and resolved after compression dressing and warfarin cessation. The second one was located in the superolateral geniculate artery and was successfully treated with transarterial embolisation. There was no recurrence in both cases. The rare occurrence and delayed presentation of pseudoaneurysms pose a diagnostic challenge. A high index of suspicion is required to make the diagnosis. Early duplex Doppler ultrasonography is recommended when patients present with atypical knee pain and prolonged swelling after a TKA.

Basimeningeal/spinal axis primitive neuroectodermal tumor without intraaxial lesion: radiological features.

Over a 12-year period, the authors encountered 2 patients with spinal axis/basimeningeal primitive neuroectodermal tumor (PNET) involving the spinal axis extramedullary, intradural compartment and the basimeninges. In neither patient was an intraaxial focus demonstrated. A 48-year-old woman had computed tomography (CT) findings of hydrocephalus and later abnormal basimeningeal enhancement. Cervical myelography revealed a low cervical intradural block. A 10-year-old boy was evaluated initially with non-contrast-enhanced CT of the brain, which revealed hydrocephalus. Contrast-enhanced CT revealed abnormal basimeningeal enhancement implicating cisternal obstruction. Subsequent magnetic resonance examination of the entire spine with and without gadolinium enhancement revealed diffuse abnormal enhancement of the spinal axis intradural, extramedullary compartment. While intraaxial PNETs are well recognized, the patients described here represent a distinctly unusual pattern of intradural spinal meningeal and basimeningeal infiltration by PNET in the absence of a demonstrable intraaxial lesion.