Electro-optical effect of unpolarized light modulation in homeoplanar structures of ferroelectric and ferrielectric liquid crystals.

A clearly expressed effect of unpolarized light electro-optical modulation by homeoplanar structures of a smectic C* ferroelectric liquid crystal (FLC) and a ferrielectric liquid crystal (FerriLC) was discovered and investigated for the first time to our knowledge. This effect of electrically controlled light scattering is insensitive to the applied voltage sign, as for polymer-dispersed nematic liquid crystals (PDLCs), but the electro-optical modulation frequency reaches the kilohertz range. Occurrence conditions and essential features of the effect, as well as its physical origin, are discussed.

[Potentially preventable causes of mortality in acute calculous cholecystitis: a population-based study]. / Potentsial'no predotvratimye prichiny letal'nosti pri ostrom kal'kuleznom kholetsistite: populyatsionnoe issledovanie.

OBJECTIVE: To analyze potentially preventable causes of mortality from acute calculous cholecystitis (ACC) at the population level. MATERIAL AND METHODS: A retrospective study of causes of ACC-related mortality was conducted. We used online survey of state hospitals and estimated fatal outcomes following ACC considering appropriate annual e-database. RESULTS: There were 1.500 deaths among 142.975 patients aged ≥18 years with acute cholecystitis. We received responses to the proposed questionnaire about 1154 deaths (76.9%). Analysis included 648 cases of ACC (K80.0). Mean age of patients was 76.0 years (31-100). There were 256 (39.5%) men and 392 (60.5%) women. ACC severity was assessed according to the Tokyo guidelines (2018). Mild (I) degree was noted in 24 (3.7%) cases, moderate (II) - 270 (41.7%), severe (III) - 354 (54.6%) patients. Cardiovascular diseases and complications caused death in mild ACC regardless of treatment method in 16 (66.7%) cases, in moderate ACC - 106 (39.3%), in severe ACC - 97 (27.4%) cases. ACC caused death in 3 (12.5%) patients with mild disease, 111 (41.1%) with moderate disease and 200 (56.5%) ones with severe disease. Postoperative complications caused death in 4 (16.7%) patients with mild disease, 29 (10.7%) ones with moderate disease and 30 (8.5%) patients with severe disease. Other causes comprised 4.1% (n=1), 8.9% (n=24) and 7.6% (n=27), respectively. Potentially preventable causes of death were identified in 33.0% of cases. CONCLUSION: ACC-related mortality is mainly associated with comorbidity in elderly and senile patients, late presentation and complicated course of disease. Delayed surgical treatment due to diagnostic and tactical problems, as well as technical intraoperative errors is potentially preventable causes of death.

[Genetic factors in degenerative disc disease]. / Rol' geneticheskikh faktorov v razvitii degenerativno-distroficheskogo porazheniya mezhpozvonkovykh diskov.

OBJECTIVE: To analyze available literature data on the role of genetic factors in degenerative disc disease. METHODOLOGY: We reviewed the PubMed, MEDLINE, Cohrane Library, e-Library databases using the following keywords: degenerative spine lesions, intervertebral disc herniation, pathogenesis, genetic regulation. RESULTS: Searching depth was 2002-2022. We reviewed 84 references. Exclusion criteria: duplicate publications, reviews without detailed description of results, opinions. Finally, we included 43 the most significant studies. CONCLUSION: There are literature data on proinflammatory cytokines, growth factors and osteodestructive processes in pathogenesis of degenerative disc disease. However, there is only fragmentary information about the role of genetic regulation of these processes. Some factors, such as microRNA, TGF-b, VEGF, MMP are still poorly understood.