Güneş pillerinde kullanılan ruthenium boyaların elektronik yapısının Hartree-Fock Kuramı ile Kuantum Monte Carlo tekniğinin birleştirilerek incelenmesi

Thesis (Master)--Izmir Institute of Technology, Physics, Izmir, 2015Includes bibliographical references (leaves: 58-61)Text in English; Abstract: Turkish and Englishxiii, 86 leavesThe Haldane-Anderson model is constructed to describe the electronic properties of a system where a transition-metal impurity atom is added into a semiconductor host material. The electric and magnetic properties of the ruthenium-based dyes are investigated by using Haldane-Anderson model in this study. Because ruthenium-based dyes are semiconductor and ruthenium atom is a transition metal and its 4d orbitals are considered as impurities for dye molecules. Density Functional Theory (DFT) and Hartree-Fock Theory (HF) was used to obtain the Haldane-Anderson model parameters of the ruthenium-based dyes. Multi-orbital Hirsch-Fye Quantum Monte Carlo (HFQMC) algorithm was used to investigate effect of onsite Coulomb interactions of impurity 4d orbitals. Firstly, the Anderson model parameters are calculated by using Hartree-Fock and Density Functional Theory. After that, the occupation numbers of 4d orbitals and the all orbital occupancies of the dye molecules are obtained by using the Hirsch-Fye Quantum Monte Carlo algorithm and the magnetization of 4d orbitals are calculated. Finally, physical meaning of our results are discussed.Yarı-iletken ev sahibi malzemenin içine geçiş metali safsızlık atomu eklenerek oluşturulan bir sistemin elektronik özelliklerini incelemek için Haldane-Anderson modeli oluşturulmuştur. Bu çalışmada ruthenium-temelli boyaların elektronik ve manyetik özellikleri Haldane-Anderson modeli kullanılarak incelenmiştir. Çünkü, ruthenium-temelli boyalar yarı iletkendir ve ruthenium atomu bir geçiş metalidir ayrıca ruthenium atomunun 4d orbitalleri boya molekülü için safsızlık olarak kabul edilmiştir. Ruthenium-temelli boyaların Haldane-Anderson modeli parameterelerini elde etmek için Yoğunluk Fonksiyoneli Kuramı ve Hartree-Fock Kuramı kullanılmıştır. 4d orbitallerindeki Coulomb etkiles¸- melerinin sistemin elektronik özelliklerine etkisini incelemek için multi-orbital Hirsch- Fye Quantum Monte Carlo algoritması kullanılmıştır. İlk olarak, Hartree-Fock ve Yoğunluk Fonksiyoneli Kuramları kullanılarak Anderson modeli parametreleri hesaplanmıs¸tır. Bundan sonra, Hirsch-Fye Kuantum Monte Carlo algoritması kullanılarak 4d orbitallerinin doluluk oranları, bütün sistemin doluluk oranları ve 4d orbitallerinin manyetizasyonları elde edilmiştir. Son olarak sonuçlarımızın fiziksel anlamları tartışılmıştır

Güneş pillerinde kullanılan ruthenium boyaların elektronik yapısının Hartree-Fock Kuramı ile Kuantum Monte Carlo tekniğinin birleştirilerek incelenmesi

Thesis (Master)--Izmir Institute of Technology, Physics, Izmir, 2015Includes bibliographical references (leaves: 58-61)Text in English; Abstract: Turkish and Englishxiii, 86 leavesThe Haldane-Anderson model is constructed to describe the electronic properties of a system where a transition-metal impurity atom is added into a semiconductor host material. The electric and magnetic properties of the ruthenium-based dyes are investigated by using Haldane-Anderson model in this study. Because ruthenium-based dyes are semiconductor and ruthenium atom is a transition metal and its 4d orbitals are considered as impurities for dye molecules. Density Functional Theory (DFT) and Hartree-Fock Theory (HF) was used to obtain the Haldane-Anderson model parameters of the ruthenium-based dyes. Multi-orbital Hirsch-Fye Quantum Monte Carlo (HFQMC) algorithm was used to investigate effect of onsite Coulomb interactions of impurity 4d orbitals. Firstly, the Anderson model parameters are calculated by using Hartree-Fock and Density Functional Theory. After that, the occupation numbers of 4d orbitals and the all orbital occupancies of the dye molecules are obtained by using the Hirsch-Fye Quantum Monte Carlo algorithm and the magnetization of 4d orbitals are calculated. Finally, physical meaning of our results are discussed.Yarı-iletken ev sahibi malzemenin içine geçiş metali safsızlık atomu eklenerek oluşturulan bir sistemin elektronik özelliklerini incelemek için Haldane-Anderson modeli oluşturulmuştur. Bu çalışmada ruthenium-temelli boyaların elektronik ve manyetik özellikleri Haldane-Anderson modeli kullanılarak incelenmiştir. Çünkü, ruthenium-temelli boyalar yarı iletkendir ve ruthenium atomu bir geçiş metalidir ayrıca ruthenium atomunun 4d orbitalleri boya molekülü için safsızlık olarak kabul edilmiştir. Ruthenium-temelli boyaların Haldane-Anderson modeli parameterelerini elde etmek için Yoğunluk Fonksiyoneli Kuramı ve Hartree-Fock Kuramı kullanılmıştır. 4d orbitallerindeki Coulomb etkiles¸- melerinin sistemin elektronik özelliklerine etkisini incelemek için multi-orbital Hirsch- Fye Quantum Monte Carlo algoritması kullanılmıştır. İlk olarak, Hartree-Fock ve Yoğunluk Fonksiyoneli Kuramları kullanılarak Anderson modeli parametreleri hesaplanmıs¸tır. Bundan sonra, Hirsch-Fye Kuantum Monte Carlo algoritması kullanılarak 4d orbitallerinin doluluk oranları, bütün sistemin doluluk oranları ve 4d orbitallerinin manyetizasyonları elde edilmiştir. Son olarak sonuçlarımızın fiziksel anlamları tartışılmıştır

GENEL CERRAHİ KLİNİĞİNDE TEDAVİ GÖREN İNTRA-ABDOMİNAL ENFEKSİYONLU HASTALARDA İNTRAVENÖZ SEFTRİAKSON VE METRONİDAZOL KOMBİNASYON TEDAVİSİ ETKİNLİĞİNİN GERİYE DÖNÜK DEĞERLENDİRMESİ

Giriş ve Amaç&nbsp;Cerrahi kliniklerinde intra-abdominal enfeksiyonlar(İAE), morbidite ve mortalitenin önemli bir nedenidir.Bu enfeksiyonların tedavisinde cerrahi olarak kaynakkontrolünün sağlanması ve uygun antibiyotikkullanımı tedavi başarısını arttırır. HastanemizdeİAE’nin ampirik tedavisinde en sık seftriakson vemetronidazol tedavisi başlanmakta olup, izlemdeklinik ve laboratuvar bulgularına göre tedavi revizeedilmektedir. Bu çalışmada ampirik seftriaksonve metronidazol kombinasyon tedavisi başlananhastalarda tedavi yanıtı değerlendirilerek, İAE günceltedavi verilerine katkı sağlanılması amaçlanmıştır.YöntemPandemi öncesi üç yıllık dönemde bir üniversitehastanesi Genel Cerrahi Servisi’nde antibiyotiktedavisi alan 12332 hasta retrospektif olarakdeğerlendirildi. İAE tanısıyla başlangıç tedavisinde 24saatten daha uzun süre seftriakson ve metronidazolkombine tedavisi alan 18 yaş ve üstü hastalar çalışmayadahil edildi. İAE’ler safra kesesi, biliopankreatiktraktus, appendiks, üst gastrointestinal sistem, kolonve diğer odaklı şeklinde değerlendirildi. Seftriaksonve metronidazol kombine tedavisi alan hastalar;Grup 1; sadece seftriakson ve metronidazol kullanantedavi değişikliği yapılmayanlar, Grup 2; seftriaksonve metronidazol tedavisi alan ve izlemde tedavideğişikliği yapılanlar olarak iki gruba ayrıldı. Verilertedavi yeterliliği ve revizyonu açısından SPSS Statistics22.0 ile analiz edildi.BulgularSeftriakson ve metronidazol ile ampirik tedavi başlanan297 (Grup 1; 243, Grup 2; 54) hasta değerlendirildi.Demografik veriler tablo 1’de sunuldu. Malignitevarlığı, son 3 ayda antibiyotik kullanımı ve son 3 aydacerrahi girişim öyküsü tedavi değişikliği açısındanistatistiksel olarak anlamlı (p&lt;0,005) saptandı.Seftriakson ve metronidazol kombinasyon tedavisininİAE lokalizasyonuna göre değişikliği ve cerrahi girişimuygulanması tablo 2’de gösterildi. Tedavi değişikliğiyapılan hastalarda kullanılan antibiyotikler şekil 1’degösterildi. Seftriakson ve metronidazol tedavisininyeterli olduğu grup ile tedavi değişikliği yapılan gruplaboratuvar verileri açısından karşılaştırıldığında 0.gün ve 48-72. saatlerde lökosit, hemoglobin, albüminve CRP değerleri benzer saptanırken; grup 1 için 5-7.günde grup 2 için tedaviyi değiştirdiğimiz gündebakılan CRP değerlerinde 5 katlık fark vardı. Grup2’deki 13 (%24) hastada tedavi revizyonu yapılmasınarağmen kaynak kontrolü sağlanması gerekti, 29(%53,7) hastada ise kaynak kontrolü sağlanmasınarağmen tedavi değişikliği yapıldı (Tablo 3).Tartışma ve SonuçAmpirik başlanmış olan seftriakson ve metronidazoltedavisi uygun kaynak kontrolü sağlandığı durumlardahastaların %80’inde tedavi revizyonu gerektirmedive başarılı oldu. İAE lokalizasyonuna göre tedavideğişikliğinin en sık biliopankreatik traktus (%37)odağında yapıldığı görüldü. Bu lokalizasyondakaynak kontrolü sağlamaya yönelik cerrahi ile birliktehastaların ¼ ünden fazlasında tedavi değişikliğiyapıldı.</p

Fusarium solani species complex infection treated with posaconazole in a liver transplantation patient; a case report

Although Fusarium spp. rarely cause infections in healthy people, they can cause fusariosis, particularly in neutropenic hematological malignancies, bone marrow transplant patients, and immunocompromised patients, such as those with acquired immune deficiency syndrome (AIDS), and rarely in solid organ transplant recipients. Here, we present a case of a liver transplant recipient with F. solani species complex (FSSC) infection treated with posaconazole. A 61-year-old man presented with multiple itchy, painful, palpable, irregular, subcutaneous nodules on the right leg and total dystrophic onychomycosis in the right toenails. Incisional skin biopsies of the lesions were performed, and the samples were sent to the pathology and mycology laboratories for analysis. The clinical isolate was identified as FSSC using phenotypic, matrix-assisted laser desorption/ionization-time of flight mass spectrometry, and genotypic methods. Liposomal amphotericin B could not be administered owing to the development of side effects; hence, the patient was treated with posaconazole for 4 months. While some nodular lesions disappeared completely under this treatment, the others showed dimensional regression. This is the first case of FSSC infection with skin and nail involvement in a non-neutropenic, liver transplant patient in Turkey. Fusariosis may develop with rare species, such as FSSC, as first reported in this case of a liver transplant patient. Regardless of the species, amphotericin B is the first choice for treating fusariosis; however, posaconazole is an effective and safe alternative to amphotericin B

Risk of hepatitis B virus reactivation in people with multiple sclerosis treated with ocrelizumab: an observational study from Turkey

Background: The risk of hepatitis B virus (HBV) reactivation remains unclear in people with multiple sclerosis (MS) receiving ocrelizumab. We aimed to assess HBV seroprevalence and reactivation risk in MS patients on ocrelizumab and to evaluate the effectiveness of antiviral prophylaxis against HBV reactivation. Methods: In this single-center, cross-sectional study, 400 people with MS receiving ocrelizumab were screened for HBV at baseline and antiviral prophylaxis was implemented based on serological results. Patients were monitored for HBV reactivation, and outcomes were analyzed. Results: Among 56 (14%) patients who had serology compatible with occult or resolved HBV infection, 49 (85.7%) received antiviral prophylaxis regularly and had no HBV reactivation during the follow-up. Reactivation of HBV occurred in 2 out of 7 (28.6%) patients who did not receive antiviral prophylaxis and in one patient who did not adhere to the prophylaxis regimen. All patients with reactivation had anti-HBs levels below 100 mIU/mL and the median titer was significantly lower than the patients with no HBV reactivation (p = 0.034). Conclusion: This study highlights a 14% anti-HBc positivity, indicating a potential risk for HBV reactivation in people with MS receiving ocrelizumab. This suggests the importance of vigilant monitoring and the implementation of prophylactic measures. Our recommendation emphasizes antiviral prophylaxis, particularly for patients with low anti-HBs, and a pre-emptive strategy for others

Vaccination Status and Outcome of Hospitalized Patients with Coronavirus Disease 2019 Before and After the Spread of Omicron Variant: An Observational Study from İzmir, Turkey

OBJECTIVE: Despite the efforts in vaccination against coronavirus disease 2019 (COVID-19), breakthrough infections occur and the need for hospitalization continues. We aimed to determine the relationship between severe acute respiratory syndrome coronavirus 2 vaccination and the severity of COVID-19 and mortality among hospitalized patients with COVID-19.MATERIAL AND METHODS: This cross-sectional study was conducted between September 2021 and February 2022 in a university hos- pital in Turkey. Hospitalized patients with COVID-19 (both in clinics and in intensive care units), ≥18 years old, and who had no previous COVID-19 were included in the study. The demographic characteristics, clinical data, vaccination status, and outcome of the patients were analyzed retrospectively and the relationship between vaccination status and mortality was determined statistically.RESULTS: Of the 674 patients, 180 (26.7%) had no vaccination, 282 (41.8%) had incomplete vaccination, and 212 (31.5%) were fully vaccinated according to the updated vaccination recommendations. While 44.0% of the patients were fully vaccinated before the occur- rence of omicron variant, 15.9% of the patients were fully vaccinated during the wave of the omicron variant. The patients with no vaccination were younger and had fewer comorbidities. The overall mortality was 31.8%. Under 50 years old, all the patients with fully vaccination survived and the patients with no vaccination or incomplete vaccination had higher (10.1%) mortality. During the omicron period, mortality was lower in fully vaccinated pateints.CONCLUSION: Immunization with and booster doses of BNT162b2 should be encouraged to protect both healthy and vulnerable populations.</p

The Effect of the Pandemic on Antifungal Use: What Has Changed?

Objective: During the COVID-19 pandemic, antimicrobial and antifungal stewardship pro-grams have lost their priority.&nbsp; Although all parenteral antifungals were used with the rec-ommendations of infectious diseases specialists in the pre-pandemic period, most consul-tations were delayed during the pandemic because of the workload of infectious diseasesspecialists. In this period, antifungal treatments in hospitalized patients were managed bymostly primary physicians. Therefore, we aimed to detect the change in the consumptionof antifungals during the pandemic.Materials and Methods:&nbsp; The data on the antifungal drug use by month and clinics, thenumber of beds, and the occupancy rate of the clinics were obtained from the hospitalinformation registration system. We defined each drug according to the World HealthOrganization Anatomical Therapeutic Chemical (WHO ATC) coding system and determinedthe defined daily dose (DDD). The antifungal consumption (DDD/ 100 bed-days) in pre-pan-demic and pandemic periods was compared.Results: During the pandemic, the antifungal consumption increased two-fold (2019:7.43;2020:18.03 DDD/100 bed-days). The highest antifungal consumption rate was in the he-matology- oncology-hematopoietic stem cell transplantation (HSCT) clinics with 2.5-fold(2019:39.86; 2020:98.48 DDD/ 100 bed-days) increase.&nbsp; Liposomal amphotericin B consump-tion made up the majority of this with a four-fold increase in the hematology-oncolo-gy-HSCT clinics.Conclusion: We detected a dramatic increase in antifungal consumption in both ICUs andinpatient clinics during pandemic. A novel antifungal stewardship approach is urgentlyneededObjective: During the COVID-19 pandemic, antimicrobial and antifungal stewardship programs have lost their priority.&nbsp; Although all parenteral antifungals were used with the recommendations of infectious diseases specialists in the pre-pandemic period, most consultations were delayed during the pandemic because of the workload of infectious diseasesspecialists. In this period, antifungal treatments in hospitalized patients were managed bymostly primary physicians. Therefore, we aimed to detect the change in the consumptionof antifungals during the pandemic.Materials and Methods:&nbsp; The data on the antifungal drug use by month and clinics, thenumber of beds, and the occupancy rate of the clinics were obtained from the hospitalinformation registration system. We defined each drug according to the World HealthOrganization Anatomical Therapeutic Chemical (WHO ATC) coding system and determinedthe defined daily dose (DDD). The antifungal consumption (DDD/ 100 bed-days) in pre-pandemic and pandemic periods was compared.Results: During the pandemic, the antifungal consumption increased two-fold (2019:7.43;2020:18.03 DDD/100 bed-days). The highest antifungal consumption rate was in the hematology- oncology-hematopoietic stem cell transplantation (HSCT) clinics with 2.5-fold(2019:39.86; 2020:98.48 DDD/ 100 bed-days) increase.&nbsp; Liposomal amphotericin B consumption made up the majority of this with a four-fold increase in the hematology-oncology-HSCT clinics.Conclusion: We detected a dramatic increase in antifungal consumption in both ICUs andinpatient clinics during pandemic. A novel antifungal stewardship approach is urgentlyneeded.</p