Profinite completion of Grigorchuk's group is not finitely presented

In this paper we prove that the profinite completion $\mathcal{\hat G}$ of the Grigorchuk group $\mathcal{G}$ is not finitely presented as a profinite group. We obtain this result by showing that H^2(\mathcal{\hat G},\field{F}_2) is infinite dimensional. Also several results are proven about the finite quotients $\mathcal{G}/ St_{\mathcal{G}}(n)$ including minimal presentations and Schur Multipliers

A heuristic procedure for a single-item dynamic lot sizing problem

An O(T) heuristic proceudre for a single-item dynamic lot sizing problem is introduced in this paper. The algorithm tries to establish the regeneration points of the problem whether either the production or the beginning inventory must be equal to zero. The proposed algorithm is very easy to implement and compares very favourably with the existing heuristic procedures. © 1988

Long-term results after Boston brace treatment in late-onset juvenile and adolescent idiopathic scoliosis

<p>Abstract</p> <p>Background</p> <p>It is recommended that research in patients with idiopathic scoliosis should focus on short- and long-term patient-centred outcome. The aim of the present study was to evaluate outcome in patients with late-onset juvenile or adolescent idiopathic scoliosis 16 years or more after Boston brace treatment.</p> <p>Methods</p> <p>272 (78%) of 360 patients, 251 (92%) women, responded to follow-up examination at a mean of 24.7 (range 16 - 32) years after Boston brace treatment. Fifty-eight (21%) patients had late-onset juvenile and 214 had adolescent idiopathic scoliosis. All patients had clinical and radiological examination and answered a standardised questionnaire including work status, demographics, General Function Score (GFS) (100 - worst possible) and Oswestry Disability Index (ODI) (100 - worst possible), EuroQol (EQ-5D) (1 - best possible), EQ-VAS (100 - best possible), and Scoliosis Research Society - 22 (SRS - 22) (5 - best possible).</p> <p>Results</p> <p>The mean age at follow-up was 40.4 (31-48) years. The prebrace major curve was in average 33.2 (20 - 57)°. At weaning and at the last follow-up the corresponding values were 28.3 (1 - 58)° and 32.5 (7 - 80)°, respectively. Curve development was similar in patients with late-onset juvenile and adolescent start. The prebrace curve increased > 5° in 31% and decreased > 5° in 26%. Twenty-five patients had surgery. Those who did not attend follow-up (n = 88) had a lower mean curve at weaning: 25.4 (6-53)°. Work status was 76% full-time and 10% part-time. Eighty-seven percent had delivered a baby, 50% had pain in pregnancy. The mean (SD) GFS was 7.4 (10.8), ODI 9.3 (11.0), EQ-5D 0.82 (0.2), EQ-VAS 77.6 (17.8), SRS-22: pain 4.1 (0.8), mental health 4.1 (0.6), self-image 3.7 (0.7), function 4.0 (0.6), satisfaction with treatment 3.7 (1.0). Surgical patients had significantly reduced scores for SRS-physical function and self-image, and patients with curves ≥ 45° had reduced self-image.</p> <p>Conclusion</p> <p>Long-term results were satisfactory in most braced patients and similar in late-onset juvenile and idiopathic adolescent scoliosis.</p

The role of specific biomarkers, as predictors of post-operative complications following flexible ureterorenoscopy (FURS), for the treatment of kidney stones: a single-centre observational clinical pilot-study in 37 patients

Abstract: Background: The number of patients diagnosed and subsequently treated for kidney stones is increasing, and as such the number of post-operative complications is likely to increase. At present, little is known about the role of specific biomarkers, following flexible ureterorenoscopy (FURS) for the surgical treatment of kidney stones. The main aim of the study was to evaluate the role of kidney and infection biomarkers, in patients undergoing FURS. Methods: Included were 37 patients (24 males, 13 females), who underwent elective FURS, for the treatment of kidney stones. Venous blood samples were collected from each patient: pre-operatively, and at 30 min, 2 and 4 h post-operatively. Changes to kidney (NGAL, Cystatin-C) and infection (MPO, PCT) biomarkers was quantified by means of ELISA, Biomerieux mini-vidas and Konelab 20 analysers. Results: Four patients developed post-operative complications (3 - UTIs with urinary retention, 1 - urosepsis. NGAL concentration increased significantly following FURS (p = 0.034). Although no significant changes were seen in Cystatin C, MPO and PCT (p ≥ 0.05) some key clinical observation were noted. Limiting factors for this study were the small number of patients recruited and restriction in blood sampling beyond 4 h. Conclusions: Although not confirmative, changes seen to biomarkers such as Cystatin C, NGAL and MPO in our observational clinical pilot-study may warrant further investigation, involving larger cohorts, to fully understand the role of these biomarkers and their potential association with post-operative complications which can develop following FURS

COVID-19 and the Global Impact on Colorectal Practice and Surgery

Background: The novel severe acute respiratory syndrome coronavirus 2 virus that emerged in December 2019 causing coronavirus disease 2019 (COVID-19) has led to the sudden national reorganization of health care systems and changes in the delivery of health care globally. The purpose of our study was to use a survey to assess the global effects of COVID-19 on colorectal practice and surgery. Materials and Methods: A panel of International Society of University Colon and Rectal Surgeons (ISUCRS) selected 22 questions, which were included in the questionnaire. The questionnaire was distributed electronically to ISUCRS fellows and other surgeons included in the ISUCRS database and was advertised on social media sites. The questionnaire remained open from April 16 to 28, 2020. Results: A total of 287 surgeons completed the survey. Of the 287 respondents, 90% were colorectal specialists or general surgeons with an interest in colorectal disease. COVID-19 had affected the practice of 96% of the surgeons, and 52% were now using telemedicine. Also, 66% reported that elective colorectal cancer surgery could proceed but with perioperative precautions. Of the 287 respondents, 19.5% reported that the use of personal protective equipment was the most important perioperative precaution. However, personal protective equipment was only provided by 9.1% of hospitals. In addition, 64% of surgeons were offering minimally invasive surgery. However, 44% reported that enough information was not available regarding the safety of the loss of intra-abdominal carbon dioxide gas during the COVID-19 pandemic. Finally, 61% of the surgeons were prepared to defer elective colorectal cancer surgery, with 29% willing to defer for ≤ 8 weeks. Conclusion: The results from our survey have demonstrated that, globally, COVID-19 has affected the ability of colorectal surgeons to offer care to their patients. We have also discussed suggestions for various practical adaptation strategies for use during the recovery period. We have presented the results of a survey used to assess the global impact of coronavirus disease 2019 (COVID-19) on the delivery of colorectal surgery. Despite accessible guidance information, our results have demonstrated that COVID-19 has significantly affected the ability of colorectal surgeons to offer care to patients. We have also discussed practical adaptation strategies for use during the recovery phase

Frontiers of spinal surgery: John Howard Moe and Robert Winter

John Howard Moe, 1905-1988 yılları arasında yaşamış ve omurga cerrahisine çok sayıda katkısı olmuş bir cerrahtır. Özellikle skolyozun modern tedavisine getirdiği yenilikler, eğitici ve açık görüşlü kişiliği onu omurga cerrahisinin öncüleri arasındaki hak ettiği yere getirmiştir. Onun en meşhur asistanı ise Robert Winter’dır.One of the surgeons who had many contribitions for spinal surgery, John Howard Moe, lived between 1905 and 1988. He is called as a frontier of spinal surgery because of his contribitions for development of modern scoliosis treatment, teachness and openminded personality. His famous resident was Robert Winter

Diagnosis and management of fractures and dislocations of thoracolumbar spine

Torakolomber bölge, vertebra kırıklarının en sık görüldüğü ve hakkında en çok yayın yapılan bölgedir. Başlıca kompresyon, patlama, fleksiyon-distraksiyon kırıkları ve kırıklı çıkıklar görülür. Bu bölge kırıkları için halihazırda tanımlayıcı, tedaviyi yönlendirici ve prognoz hakkında bilgi veren genel kabul bulmuş bir sınıflama bulunmamaktadır. Yük paylaşım sınıflaması ve TLICS, güvenirliği ve geçerliliği istatistiksel olarak kanıtlanmış tedaviyi yönlendiren önemli skorlama sistemleridir. Kompresyon kırıklarının çoğu konservatif yöntemlerle tedavi edilir. 20° üzeri kifoz ve % 50’den fazla kompresyonda cerrahi tedavi uygulanması önerilmektedir. Patlama kırıklarında cerrahi tedavi için en önemli neden Posterior Ligamentöz Kompleks (PLC)’nin yırtık olmasıdır. Nörolojik defisit ikinci cerrahi endikasyon kabul edilse de, yapılan çalışmalar cerrahi tedavinin nörolojik iyileşme üzerinde belirgin etkisi olmadığını ortaya koymaktadır. Kanıt düzeyi I ve II olan prospektif, çift kontrollü, randomize çalışmalar ve meta-analizler, konservatif ve cerrahi tedavilerin klinik sonuçlarının benzer olduğunu, posterior, anterior ve kombine cerrahi tedavilerin kifotik deformitenin düzeltilmesi, nörolojik iyileşme ve klinik sonuçlar açısından farklı olmadığını göstermektedir. Fleksiyon-distraksiyon kırıkları ve kırıklı çıkıklar ileri derecede instabil olup cerrahi olarak tedavi edilmektedirler. Sonuç olarak, torakolomber bölge kırıklarının tanımlanması ve tedavisi konusundaki karmaşa halen devan etmekte olup, evrensel kabul bulan bilgiler kısıtlı sayıdadır.Thoracolumbar region is the most frequently seen fractures of the spine and also most frequently published articles is about this region. Mainly compression, burst and flexion- distraction fractures occur in this region. There is no concensus about a classification system that gives knowledge about description, treatment guides and prognosis. Load sharing classification and TLICS are important classification systems that&amp;#8217;s validity and reliabilities are statistically proven. Most of the compression fractures are treated conservatively. Surgical treatment is recommended for more than 20&deg; kyphosis angle and more than 50 percent compression. Most important factor for surgical treatment in burst fractures is torn Posterior Ligamentous Complex (PLC). Even neurologic deficit is a known indication for surgery, the studies showed that it has no significant effect on neurologic recovery. Level I and II, double controlled, prospective, randomised studies and meta analyses showed that the clinical results are similar in both conservative and surgical treatments, and these studies also showed that there is no difference in correction of kyphotic deformity, neurologic recovery and clinical results in posterior, anterior and combined surgical procedures. Flexion-distraction fractures and fracture- dislocations are extremely unstable injuries and require surgical treatment. As a conclusion description and treatment of thoracolumbar fractures are still controversial and the universally accepted knowledge is limited yet

Correction and instrumentation techniques in surgical treatment of adolescent idiopathic scoliosis

İdiopatik skolyozun cerrahi tedavisinde son 20 yıl içinde önemli gelişmeler olmuş, hastalığın üç boyutlu patolojisi daha iyi anlaşıldıktan sonra, çoklu çengel ve tranpediküler vidaları kullanan modern segmenter sistemler kullanılmaya başlanmıştır. İdiopatik skolyoz tedavisinde, köşe taşı olan Harrington Rod sisteminin temel olarak kullandığı düzeltici kuvvet, gerdirme (distraksiyon) idi. Yeni geliştirilen 3. jenerasyon sistemlerden Dünya çapında en çok popüler olanı, bir devrim niteliğinde bir gelişme olarak görülen Cotrel Dubousset enstrümantasyon sistemiydi. Bu sistem, düzeltici manevra olarak derotasyon adı verilen manevrayı kullanıyor ve stratejik omurlara konulan çengel ve vidalara, eğriliğe uyacak şekilde eğilerek yerleştirilen rodun, eğriliğin konkav tarafına döndürülmesi işlemi ile skolyotik eğriliğin düzeltilmesine dayanıyordu. CD sistemi ve modifikasyonlarına ait yüksek düzeltme oranları bildiren yayınların yapılmasına rağmen, sistemin gövde dengesi üzerinde olumsuz etkilerinin de olduğuna dair çalışmalar yapılmıştır. 1990’ların başında bu problemleri elimine etmek üzere eğriliğin orta hatta çekilmesi yani translasyon adı verilen düzeltici manevrayı kullanan ISOLA, USS gibi sistemler kulanılmaya başlanmıştır. 2000 yılından bu yana, idiopatik skolyozun cerrahi tedavisinde 3. jenerasyon modern sistemlerin birer birer piyasadan kaybolduğu ve yeni bir gelişmenin yaşanmadığı yıllara girilmiştir. Bu yıllarda tüm bu sistemlerin uzun dönem sonuçları, hastaların tedaviden tatmin düzeyleri yayınlanmaya başlanmıştır. Bu yıllarda, ayrıca Harms ve arkadaşlarının geliştirdiği tüm seviyelere vida tespiti, Benli ve arkadaşlarının rapor ettikleri translasyon ve derotasyonu kombine kullanan güçlendirilmiş korreksiyon girişimlerine ait çalışmalar da yayınlanmıştır. Bir süredir bir duraklama içine girdiği izlenen idiopatik skolyozun cerrahi korreksiyonu konusunda önümüzdeki yıllar yeni gelişmelere gebedir.Many important developments occured in idiopatic scoliosis surgery at last 20 years, as modern segmenter systems with multipl hook and transpedicular screws were used after understanding the three dimentional pathology of the disease. The main correction force in Harrington rod system which was the &quot;corner stone&quot; of treatmant of idiopathic scoliosis was distraction. The most popular one of the 3rd generation systems in the world was Cotrel Dubousset instrumentation system. This system was using derotation maneuver as correction force and it was correcting the curve with turning the rod that was bent and placed similar to curve to the concave site of the curve. Although there were several articles that reported high correction rates with CD system and its modifications, some studies reported that it had negative effects on body equilibrium. At early 1990&amp;#8217;s, new systems as ISOLA and USS were started to use to transvers the curve to midline to eliminate this problem. Since 2000, the 3rd generation modern systems disappeared from the market, and there was not any new developments occured. At these years, articles about the long term results and satisfaction rates of the patients published. Additionally, some articles about all segment screw fixation described by Harms et al., and stronger correction occured by combination and translation described by Benli et al. published at these years. Despite unproductive period of surgical correction of idiopathic scoliosis for recent years, new developments will be expected

Scheuermann kyphosis: Aetiology, diagnosis and conservative treatment

Scheuermann kifozu, spinal kolonun puberte öncesi başlayan ve özellikle adolesan büyüme atağıyla belirginleşen deformitesidir. Hastalık radyolojik olarak artmış torasik kifoz, disk mesafesinde daralma, Schmorl nodülleri ve vertebral kamalaşmanın eşlik ettiği son plak düzensizliği şeklinde tanımlanır. Sırt ağrısı ve kozmetik yakınmalar, temel şikayetlerdir. Tedavi, deformitenin şiddeti, ağrı şikayetleri ve hasta matüritesine göre değişir. Bu çalışmada, literatür bilgileri eşliğinde tanım, etyoloji, klinik bulgular, doğal seyir ve konservatif tedavi açısından Scheuermann hastalığı değerlendirilmiş ve kişisel deneyimlerimiz de aktarılmıştır.Scheuermann&amp;#8217;s kyphosis is a deformity of the spine that develops prior to puberty and becomes most prominent during the adolescent growth spurt. Disease is identified by radiographically with increased thoracic kyphosis, disc space narrowing, Schmorl nodules, irregular end plates associated with vertebral wedging. Back pain and cosmesis are predominant clinical complaints. Treatment is dependent upon magnitude of the deformity, pain complaints and patient maturity. This rewiew article aims to glance to Scheuermann&amp;#8217;s disease in light of the literature concerning definition, etiology, clinical findings, natural course and conservative treatment