266 research outputs found

    Подавление синхронной помехи в ЯКР с модуляцией Зеемана

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    Рассмотрены принципы частотной модуляции и модуляции Зеемана в ядерном квадрупольном резонансе и показаны преимущества последней. Предложен метод устранения синхронной помехи, вызываемой переключением магнитного поля. Приведены результаты наблюдения резонансной линии ¹⁴N с достоверной формой в образце гексаметилентетрамине массой 2 г.Розглянуто принципи частотної модуляції та модуляції Зеемана в ядерному квадрупольному резонансі та показано переваги останньої. Запропоновано метод усунення синхронної завади, спричиненої перемиканням магнітного поля. Наведено результат спостереження резонансної лінії ¹⁴N з достовірною формою у зразку гексаметилентетраміну масою 2 г.The principles of frequency and Zeeman modulation in nuclear quadrupole resonance were considered, and the advantages of the latter were shown. The authors propose a method to eliminate the synchronous noise caused by switching of the magnetic field. Results of observations of the resonance line with ¹⁴N in the hexamethylenetetramine sample weighing 2 g were given

    Treatment of retained placenta with misoprostol: a randomised controlled trial in a low-resource setting (Tanzania)

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    Background: Retained placenta is one of the common causes of maternal mortality in developing countries where access to appropriate obstetrical care is limited. Current treatment of retained placenta is manual removal of the placenta under anaesthesia, which can only take place in larger health care facilities. Medical treatment of retained placenta with prostaglandins E1 (misoprostol) could be cost-effective and easy-to-use and could be a life-saving option in many low-resource settings. The aim of this study is to assess the efficacy and safety of sublingually administered misoprostol in women with retained placenta in a low resource setting. Methods: Design: Multicentered randomised, double-blind, placebo-controlled trial, to be conducted in 5 hospitals in Tanzania, Africa. Discussion: Inclusion criteria: Women with retained placenta, at a gestational age of 28 weeks or more and blood loss less than 750 ml, 30 minutes after delivery of the newborn despite active management of third stage of labour. Clinical Trial Registration: Trial Entry & Randomisation & Study Medication: After obtaining informed consent, eligible women will be allocated randomly to the treatment groups using numbered envelopes that will be randomized in variable blocks containing identical capsules with either 800 microgram of misoprostol or placebo. The drugs will be given sublingually. The women, maternal care providers and researchers will be blinded to treatment allocation. Sample Size: 117 women, to show a 40% reduction in manual removals of the placenta (p = 0.05, 80% power). The randomization will be misoprostol: placebo = 2:1. Primary Study Outcome: Expulsion of the placenta without manual removal. Secondary outcome is the number of blood transfusions. This is a protocol for a randomized trial in a low resource setting to assess if medical treatment of women with retained placenta with misoprostol reduces the incidence of manual remov

    Миф о "Братьях Карамазовых". Какой Достоевский нужен современной России?

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    В статье на основе текста романа «Братья Карамазовы» опровергается позиция И. Евлампиева, который видит в Ф.М. Достоевском по преимуществу гностического мыслителя, а также эксплицируются теоретические предпосылки тенденциозного подхода к творчеству русского писателя. Акцентируется внимание на связи романов Достоевского с православной традицией, а также значимости этой позиции для становления русского самосознания и истории России.У статті на основі тексту роману «Брати Карамазови» спростовується позиція І. Євлампієва, який вбачає у Ф.М. Достоєвському переважно гностичного мислителя, а також експлікуються теоретичні передумови тенденційного підходу до творчості російського письменника. Робиться акцент на зв’язку романів Достоєвського з православною традицією, а також на значимості цієї позиції для становлення російської самосвідомості та історії Росії.In the article the position of I. Evlampiev, who considers F.M. Dostoyevskiy, for the most part, as a gnostic thinker, is being disproved on the basis of the text of the novel “The Karamazov brothers”. Also, theoretical preconditions of tendentious understanding of the creative work of the Russian writer are being explicated. Besides, the relationship between Dostoyevskiy’s novels and orthodox tradition and the importance of this position for establishing Russian self-consciousness and the history of Russia are being indicated

    Impact of hormonal biomarkers on response to hormonal therapy in advanced and recurrent endometrial cancer

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    Inhibidores de la aromatasa; Terapia de progestinaAromatase inhibitors; Progestin therapyInhibidors de l'aromatasa; Teràpia amb progestinaBackground Approximately 20% of women with endometrial cancer have advanced-stage disease or suffer from a recurrence. For these women, prognosis is poor, and palliative treatment options include hormonal therapy and chemotherapy. Lack of predictive biomarkers and suboptimal use of existing markers for response to hormonal therapy have resulted in overall limited efficacy. Objective This study aimed to improve the efficacy of hormonal therapy by relating immunohistochemical expression of estrogen and progesterone receptors and estrogen receptor pathway activity scores to response to hormonal therapy. Study Design Patients with advanced or recurrent endometrial cancer and available biopsies taken before the start of hormonal therapy were identified in 16 centers within the European Network for Individualized Treatment in Endometrial Cancer and the Dutch Gynecologic Oncology Group. Tumor tissue was analyzed for estrogen and progesterone receptor expressions and estrogen receptor pathway activity using a quantitative polymerase chain reaction–based messenger RNA model to measure the activity of estrogen receptor–related target genes in tumor RNA. The primary endpoint was response rate defined as complete and partial response using the Response Evaluation Criteria in Solid Tumors. The secondary endpoints were clinical benefit rate and progression-free survival. Results Pretreatment biopsies with sufficient endometrial cancer tissue and complete response evaluation were available in 81 of 105 eligible cases. Here, 22 of 81 patients (27.2%) with a response had estrogen and progesterone receptor expressions of >50%, resulting in a response rate of 32.3% (95% confidence interval, 20.9–43.7) for an estrogen receptor expression of >50% and 50.0% (95% confidence interval, 35.2–64.8) for a progesterone receptor expression of >50%. Clinical benefit rate was 56.9% for an estrogen receptor expression of >50% (95% confidence interval, 44.9–68.9) and 75.0% (95% confidence interval, 62.2–87.8) for a progesterone receptor expression of >50%. The application of the estrogen receptor pathway test to cases with a progesterone receptor expression of >50% resulted in a response rate of 57.6% (95% confidence interval, 42.1–73.1). After 2 years of follow-up, 34.3% of cases (95% confidence interval, 20–48) with a progesterone receptor expression of >50% and 35.8% of cases (95% confidence interval, 20–52) with an estrogen receptor pathway activity score of >15 had not progressed. Conclusion The prediction of response to hormonal treatment in endometrial cancer improves substantially with a 50% cutoff level for progesterone receptor immunohistochemical expression and by applying a sequential test algorithm using progesterone receptor immunohistochemical expression and estrogen receptor pathway activity scores. However, results need to be validated in the prospective Prediction of Response to Hormonal Therapy in Advanced and Recurrent Endometrial Cancer (PROMOTE) study

    Developing a database for multicenter evaluation of Placenta Accreta Spectrum

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    Studies of rare, but complex clinical conditions require multicenter cooperation. The International Society for Placenta accreta spectrum (IS-PAS) have established a secure web-based database to analyze pregnancies complicated by PAS. By repeated in-person meetings of the IS-PAS, a core dataset was established. Then, a custom-made, secure online database, capable of receiving strictly anonymized patient-related textual and imaging data and allowing statistical queries was designed, tested, amended and implemented. Between 2008 and 2019, 14 IS-PAS centers across Europe and one center in the USA contributed data for all their PAS cases, containing pregnancy data for a total of 442 pregnant women. Data were analyzed by a designated data analysis sub-group of the IS-PAS. Center characteristics are presented. Based on experiences with previous versions, our new online database now allows an all-encompassing data collection. It has shown its usefulness in the current analysis project.Non peer reviewe

    Treatment Regimens for Transplant-Ineligible Patients With Newly Diagnosed Multiple Myeloma: A Systematic Literature Review and Network Meta-analysis

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    Introduction: Many treatment regimens have been evaluated in transplant-ineligible (TIE) patients with newly diagnosed multiple myeloma (NDMM). The objective of this study was to compare the efficacy of relevant therapies for the treatment of TIE patients with NDMM. Methods: Progression-free survival (PFS) and overall survival (OS) from large randomised controlled trials (RCTs) evaluating different treatment options for TIE patients with NDMM were compared in a network meta-analysis (NMA). The NMA includes recent primary and long-term OS readouts from SWOG S0777, ENDURANCE, MAIA, and ALCYONE. Relevant trials were identified through a systematic literature review. Relative efficacy measures (i.e., hazard ratios [HRs] for PFS and OS) were extracted and synthesised in random-effects NMAs. Results: A total of 122 publications describing 45 unique RCTs was identified. Continuous lenalidomide/dexamethasone (Rd) was selected as the referent comparator. Daratumumab-containing treatments (daratumumab/lenalidomide/dexamethasone [D-Rd], daratumumab/bortezomib/melphalan/prednisone [D-VMP]) and bortezomib/lenalidomide/dexamethasone (VRd) had the highest probabilities of being more effective than Rd continuous for PFS (HR: D-Rd, 0.53; D-VMP, 0.57, VRd, 0.77) and OS (HR: D-Rd, 0.68; VRd, 0.77, D-VMP, 0.78). D-Rd had the highest chance of being ranked as the most effective treatment with respect to PFS and OS. Results using a smaller network focusing on only those regimens that are relevant in Europe were consistent with the primary analysis. Conclusions: These comparative effectiveness data may help inform treatment selection in TIE patients with NDMM

    An anthropomorphic deformable phantom of the vaginal wall and cavity

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    Brachytherapy is a common treatment in cervical, uterine and vaginal cancer management. The technique is characterised by rapid developments in the fields of medical imaging, dosimetry planning and personalised medical device design. To reduce unnecessary burden on patients, assessments and training of these technologies should preferable be done using high-fidelity physical phantoms. In this study, anthropomorphic deformable phantoms of the vaginal wall and cavity were developed for image-guided adaptive brachytherapy, in which vaginal wall biomechanics were mimicked. Phantoms were produced from both silicone and polyvinyl alcohol materials. Material characterisations were performed with uniaxial tensile tests, via which Young’s moduli and toughness were quantified. In addition, the contrast between adjacent phantom layers was quantified in magnetic resonance images. The results showed that stress-strain curves of the silicone phantoms were within the range of those found in healthy human vaginal wall tissues. Sample preconditioning had a large effect on Young’s moduli, which ranged between 2.13 and 6.94 MPa in silicone. Toughness was a more robust and accurate metric for biomechanical matching, and ranged between 0.23 and 0.28 ·106 J·m-3 as a result of preconditioning. The polyvinyl alcohol phantoms were not stiff or tough enough, with a Young’s modulus of 0.16 MPa and toughness of 0.02 ·106 J·m-3. All materials used could be clearly delineated in magnetic resonance images, although the MRI sequence did affect layer contrast. In conclusion, we developed anthropomorphic deformable phantoms that mimic vaginal wall tissue and are well visible in magnetic resonance images. These phantoms will be used to evaluate the properties and to optimise the development and use of personalised brachytherapy applicators.</p

    Sentinel lymph node procedure in patients with recurrent vulvar squamous cell carcinoma:a proposed protocol for a multicentre observational study

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    BACKGROUND: Standard groin treatment in recurrent vulvar cancer consists of uni- or bilateral inguinofemoral lymphadenectomy (IFL), whereas in the primary setting women with selected unifocal tumours will undergo a sentinel lymph node (SLN) procedure. The SLN procedure results in fewer short and long-term sequelae compared to IFL, but some concerns must first be considered. Lymph drainage of the vulvar region can be affected by a previous surgery, which might reduce the number of detectable SLN nodes (feasibility) but increase the chance of encountering aberrant lymph drainage patterns such as bilateral SLNs in lateral tumours or SLNs at unexpected locations. Therefore, the SLN procedure potentially carries a higher risk of groin recurrence if a tumour positive node is not retrieved, but may also improve outcomes for women with aberrant drainage patterns. Since the relative benefits and drawbacks of the SLN procedure are still unclear we will investigate the safety of the SLN procedure in women with a first recurrent vulvar cancer. In a simultaneously started registration study we prospectively gather information on women with a first recurrence of vulvar cancer ineligible for the SLN procedure. METHOD: In this prospective multicentre observational study all women with a first recurrence of vulvar cancer will be asked to consent to the collection of information on their diagnostics, treatment and outcome, and to complete quality of life and lymph oedema questionnaires. Women with unifocal tumours smaller than 4 cm and unsuspicious groin nodes will be offered the SLN procedure, with follow-up every 3 months together with imaging at 6 and 12 months when the SLN is tumour negative. The primary outcome is groin recurrence within 2 years of initial surgery. A total of 150 women with negative SLNs will be required to demonstrate safety, a stopping rule will apply and an extensive statistical analysis has been designed. DISCUSSION: Should the SLN procedure prove feasible and safe in recurrent vulvar cancer, it will be available for implementation in clinics worldwide. The inclusion of women ineligible for the SLN procedure in the current prospective study will help to bridge knowledge gaps and define future research questions. TRIAL REGISTRATION: Medical Ethical Committee approval number NL70149.078.19 (trial protocol version 2.0, date March 2nd, 2020). Affiliation: Erasmus Medical Centre. Dutch trial register NL8467. Date of registration 19.03.2020
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