Laplace Transform Inversion and Time-Discretization Methods for Evolution Equations

In this dissertation, we introduce Post-Widder-type inversion methods for the Laplace transform based on A-stable rational approximations of the exponential function. Since the results hold for Banach-space-valued functions, they yield efficient time-discretization methods for evolution equations of convolution type; e.g., linear first and higher order abstract Cauchy problems, inhomogeneous Cauchy problems, delay equations, Volterra and integro-differential equations, and problems that can be re-written as an abstract Cauchy problem on an appropriate state space

ON SUBDIAGONAL RATIONAL PADE APPROXIMATIONS AND THE BRENNER-THOMEE APPROXIMATION THEOREM FOR OPERATOR SEMIGROUPS

The computational powers of Mathematica are used to prove polynomial identities that are essential to obtain growth estimates for subdiagonal rational Pade approximations of the exponential function and to obtain new estimates of the constants of the Brenner-Thomee Approximation Theorem of Semigroup Theory

Crystal structure of cis-copper(II) complex with N-(di-n-propylcarbamothioyl)cyclohexanecarboxamide ligand

Copper(II) complex, cis-[Cu(L-κ2S,O)2] of N-(di-n-propylcarbamothioyl)cyclohexane carboxamide ligands (HL) has been synthesized and structurally characterized by various spectroscopic techniques and single crystal X-ray diffraction crystallography. The cis-[Cu(L-κ2S,O)2], C28H50CuN4O2S2: Monoclinic, space group P21/n (no. 14), a = 10.025(2) Å, b = 21.724(4) Å, c = 14.848(3) Å, β = 100.60(3)°, Z = 4, Dcalc = 1.259 g/cm3, 22069 reflections measured (5.88° ≤ 2Θ ≤ 50.2°), 5639 unique (Rint = 0.0630, Rsigma = 0.0678) which were used in all calculations. The final R1 was 0.0488 (≥2σ(I)) and wR2 was 0.1277 (all data). Single crystal analysis revealed that a square-planar coordination geometry is formed around the copper atom by two sulphur and two oxygen atoms of the related ligand, which are in a cis configuration

Mental Foramenin Lokalizasyonun Radyografik Olarak Değerlendirilmesi

Amaç: Mental foramenin yerinin tam olarak lokalize edilmesi alt çeneye uygulanan cerrahi operasyonlar açısından kritik bir öneme sahiptir. Lokalizasyonunun çeşitliliği özellikle implant cerrahisi gibi bazı operasyonlar sırasında komplikasyona sebep olabilir. Bu çalışmanın amacı Sivas ilindeki hastalardan elde edilen dijital panoramik röntgenleri değerlendirerek, mental foramenin lokalizasyonunu araştırmaktır. Gereç ve yöntem: Bu çalışmada, 360 hastanın dijital panoramik röntgeni retrospektif olarak incelenmiştir. Panoramik röntgenlerde, mental foramenin farklı lokalizasyonları cinsiyet ayrımı gözeterek, simetrik ve asimetrik olarak değerlendirilmiştir. Ayrıca mental foramenin alveoler kret tepesine ve alt çene alt kenarına olan ortalama uzaklıkları incelenmiştir. Bulgular: Mental foramen hastaların % 59,4’ünde birinci ve ikinci küçük azı dişleri arasında ,% 37,2’sinde ikinci küçük azı diş aksının hizasında olduğu belirlendi. Erkeklerin % 64,6’sında ve kadınların % 55,1’ninde mental foramenin birinci ve ikinci küçük azı dişleri arasında olduğu bulundu. Mental foramenin hastaların % 80,3’ünde simetrik olduğu saptandı. Mental foramenin sağ tarafta alveoler kret tepesine 16,79 mm ve alt çene alt kenarına 12,46 mm ortalama uzaklıkta olduğu belirlendi. Sol tarafta ise foramenin alveoler kret tepesine 16,80 mm alt çene alt kenarına 12,58 mm ortalama uzaklıkta olduğu bulundu. Sonuç: Sonuç olarak, panoramik radyografide Sivas il genelinde mental foramenin en sık olarak birinci ve ikinci küçük azı dişleri arasında lokalize olduklar ve diğer pozisyonlarda lokalizasyonlarının ise çok düşük olduğu görülmüştür. Vakaların çoğunda bilateral olarak simetrik olduğu görülmüştür

Konjenital Olarak Eksik Olan İkinci Küçük Azıların Prevalansı

Amaç: Bu çalışmanın amacı, konjenital olarak kayıp olan ikinci küçük azıların cinsiyet ve lokalizasyona göre dağılımı ve prevalansını değerlendirmektir. Gereç ve Yöntem: Bu çalışma, Ocak 2000 ile Aralık 2009 yılları arasında Cumhuriyet Üniversitesi Diş Hekimliği Fakültesi Ağız Diş Çene Hastalıkları ve Cerrahisi Anabilim Dalına başvuran 7753 (4573 kadın, 3180 erkek) hastanın panoramik ve klinik kayıtları üzerinde yürütüldü. Konjenital olarak ikinci küçük azıları eksik olan 52 hasta tespit edildi. Olgular cinsiyet, lokalizasyon, tek ya da çift taraflı meydana gelmesi ve anomali ile ilişkileri yönünden araştırıldı. Bulgular: 7753 panoramik röntgende, 13’ü erkek 39’u kadın olmak üzere toplam 52 olguda, 70 adet ikinci küçük azı dişinin konjenital eksikliği saptandı. İkinci küçük azı diş eksikliği prevalansının kadınlarda erkeklere göre 3 kat, alt çenede üst çeneye göre 4 kat daha fazla olduğu belirlendi. Konjenital bir anomali saptanmadı. Sonuç: Bu çalışmada popülasyonda ikinci küçük azıların doğumsal eksikliğinin prevalansı %0,67 olarak bulundu

Successful Treatment of Enterocutaneous Fistula in a Hemodialysis Patient with Somatostatin

Although cysticercosis is the most common parasitic disease affecting the central nervous system, spinal cysticercosis is rare. A rare form of spinal cysticercosis involving the whole spinal canal is presented. A 45-year-old Korean male had a history of intracranial cysticercosis and showed progressive paraparesis. Spinal magnetic resonance scan showed multiple cysts compressing the spinal cord from C1 to L1. Three different levels (C1-2, T1-3, and T11-L1) required operation. Histopathological examination confirmed cysticercosis. The patient improved markedly after surgery

Co-circulation of West Nile virus and distinct insect-specific flaviviruses in Turkey

Background: Active vector surveillance provides an efficient tool for monitoring the presence or spread of emerging or re-emerging vector-borne viruses. This study was undertaken to investigate the circulation of flaviviruses. Mosquitoes were collected from 58 locations in 10 provinces across the Aegean, Thrace and Mediterranean Anatolian regions of Turkey in 2014 and 2015. Following morphological identification, mosquitoes were pooled and screened by nested and real-time PCR assays. Detected viruses were further characterised by sequencing. Positive pools were inoculated onto cell lines for virus isolation. Next generation sequencing was employed for genomic characterisation of the isolates. Results: A total of 12,711 mosquito specimens representing 15 species were screened in 594 pools. Eleven pools (2%) were reactive in the virus screening assays. Sequencing revealed West Nile virus (WNV) in one Culex pipiens (s.l.) pool from Thrace. WNV sequence corresponded to lineage one clade 1a but clustered distinctly from the Turkish prototype isolate. In 10 pools, insect-specific flaviviruses were characterised as Culex theileri flavivirus in 5 pools of Culex theileri and one pool of Cx. pipiens (s.l.), Ochlerotatus caspius flavivirus in two pools of Aedes (Ochlerotatus) caspius, Flavivirus AV-2011 in one pool of Culiseta annulata, and an undetermined flavivirus in one pool of Uranotaenia unguiculata from the Aegean and Thrace regions. DNA forms or integration of the detected insect-specific flaviviruses were not observed. A virus strain, tentatively named as “Ochlerotatus caspius flavivirus Turkey”, was isolated from an Ae. caspius pool in C6/36 cells. The viral genome comprised 10,370 nucleotides with a putative polyprotein of 3,385 amino acids that follows the canonical flavivirus polyprotein organisation. Sequence comparisons and phylogenetic analyses revealed the close relationship of this strain with Ochlerotatus caspius flavivirus from Portugal and Hanko virus from Finland. Several conserved structural and amino acid motifs were identified. Conclusions: We identified WNV and several distinct insect-specific flaviviruses during an extensive biosurveillance study of mosquitoes in various regions of Turkey in 2014 and 2015. Ongoing circulation of WNV is revealed, with an unprecedented genetic diversity. A probable replicating form of an insect flavivirus identified only in DNA form was detected

Goodbye Hartmann trial: a prospective, international, multicenter, observational study on the current use of a surgical procedure developed a century ago

Background: Literature suggests colonic resection and primary anastomosis (RPA) instead of Hartmann's procedure (HP) for the treatment of left-sided colonic emergencies. We aim to evaluate the surgical options globally used to treat patients with acute left-sided colonic emergencies and the factors that leading to the choice of treatment, comparing HP and RPA. Methods: This is a prospective, international, multicenter, observational study registered on ClinicalTrials.gov. A total 1215 patients with left-sided colonic emergencies who required surgery were included from 204 centers during the period of March 1, 2020, to May 31, 2020. with a 1-year follow-up. Results: 564 patients (43.1%) were females. The mean age was 65.9 ± 15.6 years. HP was performed in 697 (57.3%) patients and RPA in 384 (31.6%) cases. Complicated acute diverticulitis was the most common cause of left-sided colonic emergencies (40.2%), followed by colorectal malignancy (36.6%). Severe complications (Clavien-Dindo ≥ 3b) were higher in the HP group (P < 0.001). 30-day mortality was higher in HP patients (13.7%), especially in case of bowel perforation and diffused peritonitis. 1-year follow-up showed no differences on ostomy reversal rate between HP and RPA. (P = 0.127). A backward likelihood logistic regression model showed that RPA was preferred in younger patients, having low ASA score (≤ 3), in case of large bowel obstruction, absence of colonic ischemia, longer time from admission to surgery, operating early at the day working hours, by a surgeon who performed more than 50 colorectal resections. Conclusions: After 100 years since the first Hartmann's procedure, HP remains the most common treatment for left-sided colorectal emergencies. Treatment's choice depends on patient characteristics, the time of surgery and the experience of the surgeon. RPA should be considered as the gold standard for surgery, with HP being an exception

Infected pancreatic necrosis: outcomes and clinical predictors of mortality. A post hoc analysis of the MANCTRA-1 international study

: The identification of high-risk patients in the early stages of infected pancreatic necrosis (IPN) is critical, because it could help the clinicians to adopt more effective management strategies. We conducted a post hoc analysis of the MANCTRA-1 international study to assess the association between clinical risk factors and mortality among adult patients with IPN. Univariable and multivariable logistic regression models were used to identify prognostic factors of mortality. We identified 247 consecutive patients with IPN hospitalised between January 2019 and December 2020. History of uncontrolled arterial hypertension (p = 0.032; 95% CI 1.135-15.882; aOR 4.245), qSOFA (p = 0.005; 95% CI 1.359-5.879; aOR 2.828), renal failure (p = 0.022; 95% CI 1.138-5.442; aOR 2.489), and haemodynamic failure (p = 0.018; 95% CI 1.184-5.978; aOR 2.661), were identified as independent predictors of mortality in IPN patients. Cholangitis (p = 0.003; 95% CI 1.598-9.930; aOR 3.983), abdominal compartment syndrome (p = 0.032; 95% CI 1.090-6.967; aOR 2.735), and gastrointestinal/intra-abdominal bleeding (p = 0.009; 95% CI 1.286-5.712; aOR 2.710) were independently associated with the risk of mortality. Upfront open surgical necrosectomy was strongly associated with the risk of mortality (p < 0.001; 95% CI 1.912-7.442; aOR 3.772), whereas endoscopic drainage of pancreatic necrosis (p = 0.018; 95% CI 0.138-0.834; aOR 0.339) and enteral nutrition (p = 0.003; 95% CI 0.143-0.716; aOR 0.320) were found as protective factors. Organ failure, acute cholangitis, and upfront open surgical necrosectomy were the most significant predictors of mortality. Our study confirmed that, even in a subgroup of particularly ill patients such as those with IPN, upfront open surgery should be avoided as much as possible. Study protocol registered in ClinicalTrials.Gov (I.D. Number NCT04747990)