Effect of chemically induced fracturing on the ice nucleation activity of alkali feldspar

Feldspar is an important constituent of airborne mineral dust. Some alkali feldspars exhibit particularly high ice nucleation (IN) activity. This has been related to structural similarities of the ice (101¯0) prism planes and the (100) planes of alkali feldspar. Here the effect of generating feldspar surfaces with close to (100) orientation by means of chemically induced fracturing on the IN activity of alkali feldspar was investigated experimentally. To this end, gem-quality K-rich alkali feldspar was shifted towards more Na-rich compositions by cation exchange with an NaCl–KCl salt melt at 850 ∘C. By this procedure, a system of parallel cracks with an orientation close to the (100) plane of the feldspar was induced. Droplet-freezing assay experiments performed on grain mounts of the cation-exchanged alkali feldspars revealed an increase in the overall density of ice-nucleating active site (INAS) density with respect to the untreated feldspar. In addition, annealing at 550 ∘C subsequent to primary cation exchange further enhanced the INAS density and led to IN activity at exceptionally high temperatures. Although very efficient in experiment, fracturing by cation exchange with an alkali halide salt is unlikely to be of relevance in the conditioning of alkali feldspars in nature. However, parting planes with similar orientation as the chemically induced cracks may be generated in lamellar microstructures resulting from the exsolution of initially homogeneous alkali feldspar, a widespread phenomenon in natural alkali feldspar known as perthite formation. Perthitic alkali feldspars indeed show the highest IN activity. We tentatively ascribe this phenomenon to the preferential exposure of feldspar crystal surfaces oriented sub-parallel to (100)

Long-term results of radiotherapy for periarthritis of the shoulder: a retrospective evaluation

<p>Abstract</p> <p>Background</p> <p>To evaluate retrospectively the results of radiotherapy for periarthritis of the shoulder</p> <p>Methods</p> <p>In 1983–2004, 141 patients were treated, all had attended at least one follow-up examination. 19% had had pain for several weeks, 66% for months and 14% for years. Shoulder motility was impaired in 137/140 patients. Nearly all patients had taken oral analgesics, 81% had undergone physiotherapy, five patients had been operated on, and six had been irradiated. Radiotherapy was applied using regular anterior-posterior opposing portals and Co-60 gamma rays or 4 MV photons. 89% of the patients received a total dose of 6 Gy (dose/fraction of 1 Gy twice weekly, the others had total doses ranging from 4 to 8 Gy. The patients and the referring doctors were given written questionnaires in order to obtain long-term results. The mean duration of follow-up was 6.9 years [0–20 years].</p> <p>Results</p> <p>During the first follow-up examination at the end of radiotherapy 56% of the patients reported pain relief and improvement of motility. After in median 4.5 months the values were 69 and 89%, after 3.9 years 73% and 73%, respectively. There were virtually no side effects. In the questionnaires, 69% of the patients reported pain relief directly after radiotherapy, 31% up to 12 weeks after radiotherapy. 56% of the patients stated that pain relief had lasted for "years", in further 12% at least for "months".</p> <p>Conclusion</p> <p>Low-dose radiotherapy for periarthropathy of the shoulder was highly effective and yielded long-lasting improvement of pain and motility without side effects.</p

Determinants of multimorbidity in low‐ and middle‐income countries: A systematic review of longitudinal studies and discovery of evidence gaps

Summary: Multimorbidity—the coexistence of at least two chronic health conditions within the same individual—is an important global health challenge. In high‐income countries (HICs), multimorbidity is dominated by non‐communicable diseases (NCDs); whereas, the situation may be different in low‐ and middle‐income countries (LMICs), where chronic communicable diseases remain prominent. The aim of this systematic review was to identify determinants (including risk and protective factors) and potential mechanisms underlying multimorbidity from published longitudinal studies across diverse population‐based or community‐dwelling populations in LMICs. We systematically searched three electronic databases (Medline, Embase, and Global Health) using pre‐defined search terms and selection criteria, complemented by hand‐searching. All titles, abstracts, and full texts were independently screened by two reviewers from a pool of four researchers. Data extraction and reporting were according to Preferred Reporting Items for Systematic Reviews and Meta‐Analyses (PRISMA) guidelines. Methodological quality and risk of bias assessment was performed using the Newcastle‐Ottawa Scale for cohort studies. Data were summarized using narrative synthesis. The search yielded 1782 records. Of the 52 full‐text articles included for review, 8 longitudinal population‐based studies were included for final data synthesis. Almost all studies were conducted in Asia, with only one from South America and none from Africa. All studies were published in the last decade, with half published in the year 2021. The definitions used for multimorbidity were heterogeneous, including 3–16 chronic conditions per study. The leading chronic conditions were heart disease, stroke, and diabetes, and there was a lack of consideration of mental health conditions (MHCs), infectious diseases, and undernutrition. Prospectively evaluated determinants included socio‐economic status, markers of social inequities, childhood adversity, lifestyle behaviors, obesity, dyslipidemia, and disability. This review revealed a paucity of evidence from LMICs and a geographical bias in the distribution of multimorbidity research. Longitudinal research into epidemiological aspects of multimorbidity is warranted to build up scientific evidence in regions beyond Asia. Such evidence can provide a detailed picture of disease development, with important implications for community, clinical, and interventions in LMICs. The heterogeneity in study designs, exposures, outcomes, and statistical methods observed in the present review calls for greater methodological standardisation while conducting epidemiological studies on multimorbidity. The limited evidence for MHCs, infectious diseases, and undernutrition as components of multimorbidity calls for a more comprehensive definition of multimorbidity globally

A Corporate Social Entrepreneurship Approach to Market-Based Poverty Reduction

In this article, we aim to conceptualize a market-based approach to poverty reduction from a corporate social entrepreneurship (CSE) perspective. Specifically, we describe some market-based initiatives at the base of the economic pyramid and relate them to the social entrepreneurship literature. We refer to the entrepreneurial activities of multinational corporations that create social value as CSE. We then conceptualize CSE according to the corporate entrepreneurship and social entrepreneurship domains and shed light on how corporations can implement CSE. Finally, by reviewing relevant literature, we propose some of the factors that can stimulate CSE in organizations and some of the benefits companies can gain by implementing CSE