scholarly journals Design of a hybrid refractive-diffractive telescope for observations in UV

2020 ◽  
Vol 50 (2-3) ◽  
pp. 159-168
Author(s):  
Grzegorz Fluder

Abstract Telescopes are one of the common types of satellite payloads. They are used both for Earth and astronomical observations. By using space telescopes it is possible to eliminate the negative effect of the atmosphere on image quality. Additionally, observations in some spectral ranges can be performed only from space due to absorption of certain wavelengths in the atmosphere. One such range is UV below 300 nm, which is of particular interest when it comes to the investigation of hot objects. Reflective telescopes are commonly used in this spectral range, although many classical designs are limited in their useful field of view to values below 1°. In this paper a hybrid refractive-diffractive telescope design working in a 200 nm – 300 nm spectral range with a field of view 10°×10° is proposed. Its performance is compared to purely refractive and reflective systems and significant improvement in the imaging quality of the system and decrease of its size is shown. The choice of the diffractive element type is explained. Parameters of the systems are based on the requirements for a proposed Polish mission UVSat which aims to enable long-term observations of a large number of stars exhibiting UV variance.

2021 ◽  
Vol 30 ◽  
pp. 096368972110360
Author(s):  
Daniel Lysak ◽  
Michaela Brychtová ◽  
Martin Leba ◽  
Miroslava Čedíková ◽  
Daniel Georgiev ◽  
...  

Cryopreserved haematopoietic progenitor cells are used to restore autologous haematopoiesis after high dose chemotherapy. Although the cells are routinely stored for a long period, concerns remain about the maximum storage time and the possible negative effect of storage on their potency. We evaluated the effect of cryopreservation on the quality of peripheral stem cell grafts stored for a short (3 months) and a long (10 years) period and we compared it to native products.The viability of CD34+ cells remained unaffected during storage, the apoptotic cells were represented up to 10% and did not differ between groups. The clonogenic activity measured by ATP production has decreased with the length of storage (ATP/cell 1.28 nM in native vs. 0.63 in long term stored products, P < 0.05). Only borderline changes without statistical significance were detected when examining mitochondrial and aldehyde dehydrogenase metabolic activity and intracellular pH, showing their good preservation during cell storage. Our experience demonstrates that cryostorage has no major negative effect on stem cell quality and potency, and therefore autologous stem cells can be stored safely for an extended period of at least 10 years. On the other hand, long term storage for 10 years and longer may lead to mild reduction of clonogenic capacity. When a sufficient dose of stem cells is infused, these changes will not have a clinical impact. However, in products stored beyond 10 years, especially when a low number of CD34+ cells is available, the quality of stem cell graft should be verified before infusion using the appropriate potency assays.


2017 ◽  
Vol 61 (No. 8) ◽  
pp. 443-448 ◽  
Author(s):  
DA Bala ◽  
E. Eraslan ◽  
I. Akyazi ◽  
EE Ekiz ◽  
M. Ozcan ◽  
...  

Studies on the frozen storage of human blood products have benefited veterinary transfusion medicine in recent years, but the long-term cryopreservation of canine red blood cells (RBCs) has not yet been thoroughly investigated. Further, no studies are available with respect to the frozen storage of leukocyte-depleted canine red blood cells (LD-RBCs). The objective of the current study was to investigate time-dependent effects of long-term frozen storage on leukocyte-depleted canine RBCs. Twelve healthy adult dogs meeting the criteria for blood transfusion were used in the study. Whole blood samples (450 ± 45 ml) collected from each dog were centrifuged for 5 min at 22 °C and 4200 × g in a cryogenic microcentrifuge and concentrated RBC (pRBC) suspensions were obtained. Leukocyte depletion was achieved by filtration (2.6 log<sub>10</sub>). Then, the filtrated samples were prewashed three times in 0.9% NaCl solution and were allocated into three subgroups to be evaluated at three different time points (Day 0, Month 4 and Month 6). The samples for cryopreservation were subjected to glycerolisation and then stored at –80 °C for 4- and 6-month periods. At the end of this period pRBC units were thawed by manual agitation in a water bath maintained at 36–38 °C, centrifuged and then washed in a consecutive series of 12%, 1.6% and 0.9% of NaCl + 0.2 dextrose solutions. 2,3-Diphosphoglycerate (2,3-DPG), adenosine triphosphate (ATP), supernatant haemoglobin (SupHb), sodium (Na<sup>+</sup>) and potassium (K<sup>+</sup>) levels, residual glycerol concentrations and haemograms of thawed and deglycerolised pRBC samples were evaluated together with those of Day 0. Sterility tests were performed on all samples for bacterial contamination. No statistically significant differences were noted except for Hct and SupHb levels. No bacterial contamination was noted in any of the samples on the basis of sterility tests. It was found that the described glycerolisation procedure could be a method of choice in the cryopreservation of leukocyte-depleted pRBCs (LD-pRBCs) since no negative effect was observed on the quality of the products and long-term frozen storage did not cause RBC destruction.


2012 ◽  
Vol 30 (30) ◽  
pp. 3712-3719 ◽  
Author(s):  
Sharon L. Bober ◽  
Veronica Sanchez Varela

Sexual dysfunction is one of the most common and distressing consequences of cancer treatment. Although some treatment-related sexual adverse effects are short-term, many survivors face long-term effects such as treatment-induced menopause, altered gonadal function, and significant surgical disfigurement. Profound sexual dysfunction has been shown to have a significant negative effect on quality of life. Although these problems have been well documented and there are a range of intervention strategies that can help patients cope with treatment-related sexual problems, many survivors do not feel prepared for potential sexual changes and often do not receive adequate support to manage sexual dysfunction. Numerous barriers contribute to this underprovided aspect of survivorship care, including lack of provider training and access to readily available resources. In addition, psychological, relational, and cultural factors significantly influence sexuality but are often not taken into consideration in research and clinical practice. By taking an integrative approach and providing survivors with appropriate screening, information, and support, sexual dysfunction and accompanying distress can be significantly alleviated. In this article, we aim to provide a concise review of the most common sexual problems experienced by survivors and highlight some of the most promising evidence-based practices for assessment and intervention. We also address limitations encountered in research and practice and explore future directions, including suggestions for adopting an integrative treatment model to address sexual dysfunction in a cancer survivorship treatment setting.


Medicina ◽  
2021 ◽  
Vol 57 (12) ◽  
pp. 1340
Author(s):  
Claudia Mehedintu ◽  
Francesca Frincu ◽  
Andreea Carp-Veliscu ◽  
Ramona Barac ◽  
Dumitru-Cristinel Badiu ◽  
...  

Malignant hematological conditions have recognized an increased incidence and require aggressive treatments. Targeted chemotherapy, accompanied or not by radiotherapy, raises the chance of defeating the disease, yet cancer protocols often associate long-term gonadal consequences, for instance, diminished or damaged ovarian reserve. The negative effect is directly proportional to the types, doses, time of administration of chemotherapy, and irradiation. Additionally, follicle damage depends on characteristics of the disease and patient, such as age, concomitant diseases, previous gynecological conditions, and ovarian reserve. Patients should be adequately informed when proceeding to gonadotoxic therapies; hence, fertility preservation should be eventually regarded as a first-intention procedure. This procedure is most beneficial when performed before the onset of cancer treatment, with the recommendation for embryos or oocytes’ cryopreservation. If not feasible or acceptable, several options can be available during or after the cancer treatment. Although not approved by medical practice, promising results after in vitro studies increase the chances of future patients to protect their fertility. This review aims to emphasize the mechanism of action and impact of chemotherapy, especially the one proven to be gonadotoxic, upon ovarian reserve and future fertility. Reduced fertility or infertility, as long-term consequences of chemotherapy and, particularly, following bone marrow transplantation, is often associated with a negative impact of recovery, social and personal life, as well as highly decreased quality of life.


2004 ◽  
Vol 8 (2_suppl) ◽  
pp. 20-25
Author(s):  
Alan Menter

Patients with psoriasis may experience impaired psychosocial mental status regardless of their objectively defined disease severity. The objective clinical measures of disease that are commonly used to evaluate a patient's psoriasis fail to take into account the effect of psoriasis on patients' quality of life (QOL). As a result, a significant number of patients are dissatisfied with conventional treatments and are searching for new options. A high unmet need for effective and safe long-term therapies that can also improve patients' QOL exists in psoriasis. Alefacept, a selective biologic agent specifically designed for the treatment of psoriasis, provides improvement in both the physical (as measured by the Psoriasis Area and Severity Index) and mental (as measured by the Dermatology Life Quality Index) aspects of the disease. Additionally, alefacept is extremely well tolerated, with no negative effect on QOL, and the improvement in QOL is maintained off-treatment, which is consistent with its remittive effects on the disease. Alefacept helps fulfill the needs of psoriasis patients by providing efficacy, safety, off-treatment remissions, and improvement in QOL.


2007 ◽  
Vol 71 (3) ◽  
pp. 124-142 ◽  
Author(s):  
Christian Homburg ◽  
Ove Jensen

The literature is divided on whether differences between the thought worlds of marketing and sales are deleterious or beneficial. This article empirically investigates various facets of thought-world differences and their effects on various outcomes. It confirms that, in general, differences hamper the cooperation between marketing and sales, which leads to a lower market performance of the business unit. However, some facets of thought-world differences enhance the market performance of the business unit through a direct effect that outweighs the negative effect mediated by the quality of cooperation between marketing and sales. Market performance is enhanced if one side plays the customers' advocate while the other plays the products' advocate. Market performance is also enhanced if one side plays the advocate of short-term considerations while the other plays the advocate of long-term considerations. In contrast, differences between marketing and sales in regard to product knowledge and interpersonal skills are deleterious to market performance. Thus, the kind of difference makes a difference.


2020 ◽  
Author(s):  
Chunji Wang ◽  
Carolee Winstein ◽  
David Z. D’Argenio ◽  
Nicolas Schweighofer

AbstractIn motor skill learning, the greater the dose of training, the greater the efficacy of training, the lower the efficiency of training, and the better the long-term retention. Whether such principles apply to motor training after stroke is unclear. Here, we developed novel mixed-effects models of the change in the quality of arm movements during and following training fitted to data from a recent randomized controlled trial of the effect of the dose of training in chronic stroke. Analysis of the model’s learning and retention rates demonstrated an increase in efficacy of training with greater doses, a decrease in efficiency of training with both additional doses and additional bouts of training, and fast initial decay following training. Two additional effects modulated retention: a positive “self-training” effect, and an un-expected negative effect of dose. Our results suggest that for patients with sufficient arm use post-training, self-training will further improve use, but additional therapy may be in vain.


2021 ◽  
Author(s):  
Parviz Molavi ◽  
Saeid Sadeghieh-Ahary ◽  
Mohsen Rezaeian ◽  
Elmira Taghizadeh ◽  
Elhameh Nasiri ◽  
...  

Abstract Background: In addition to bearing on the patients and public, schizophrenia has a tremendous impact on families and caregivers. Its negative consequence has been studied as a burden. In this study, by doing qualitative analysis, we examined the experiences of Iranian families within the Ardabil, Iran, living with patients with schizophrenia. Method: This research was a qualitative study, and data collection was done through an in-depth, unstructured interview. Twenty family members of patients with schizophrenia were interviewed, and data were analyzed by the conventional qualitative content analysis. Results: The major themes of the interviews were classified into 3-level codes. Six subthemes were found in the experiences of patients with schizophrenia families, namely stigma, sense of shame, isolation, need for support, and lack of awareness, and poor quality of life, which were combined and classified into one main category named "living in hell".Conclusions: The findings showed that schizophrenia has an impressive negative effect on the families' welfare; thus, it highlights the necessity to provide interventions to help them adapt to this disorder. The results also highlight that caring is more demanding for families of long-term disease patients.


2017 ◽  
Vol 11 (1) ◽  
pp. 38-47 ◽  
Author(s):  
VCG Hopkinson ◽  
I Pearce

Overactive bladder syndrome (OAB) has a high prevalence within the population and has a negative effect on quality of life. Although the precise pathophysiology has yet to be fully elucidated, pharmacotherapeutic agents have been developed targeting two main pathways, antimuscarinic drugs and β3-adrenoreceptor agonists. Conservative management strategies, for example, bladder training, should be used as first-line treatment, with pharmacotherapy used as an adjunct if this is insufficiently effective. Antimuscarinics have a moderate effect on treating the symptoms of OAB, are associated with side effects, particularly dry mouth, and have low adherence rates in the long term. No single agent has consistently shown superiority over another. Antimuscarinics can affect cognition and may contribute to the anticholinergic burden in elderly patients. Mirabegron, a β3-agonist, appears to be as effective as antimuscarinics in improving symptoms of OAB with fewer side effects and improved adherence, and is currently recommended if treatment with antimuscarinics has failed. A combination of an antimuscarinic and β3-agonist may be worth considering if symptoms remain refractory or to reduce the side-effect profile associated with higher doses of antimuscarinics. Level of evidence: Not applicable.


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