Investigation of Resistance Switching and Synaptic Properties of VO x for Neuromorphic Applications.

The taking run on artificial intelligence in the last decades is based on the von Neumann architecture where memory and computation units are separately located from each other. This configuration causes a large amount of energy and time to be dissipated during data transfer between these two units, in contrast to synapses in biological neurons. A new paradigm has been proposed inspired by biological neurons in human brains, known as neuromorphic computing. Due to the unusual current-voltage characteristic of memristor devices such as pinched hysteresis loops, memristors are considered a key element of neuromorphic architecture. In this study, we report the basic current-voltage characteristic of the memristor devices in the form of Si/SiO2/Pt(30 nm)/VO x (3, 13, 25 nm)/Pt (30 nm) sandwich structure. Synaptic functions such as spike-time-dependent plasticity (STDP), paired-pulse facilitation (PPF), long-term potentiation (LTP), and long-term depression (LTD) of memristor devices were examined in detail. The oxide layer VO x has been grown by using the VO2 target in a pulsed laser deposition (PLD) chamber. The composition and oxidation states of the oxide layer were examined using the X-ray photoelectron spectroscopy (XPS) technique. The status of oxygen vacancies, which play an active role in the operation of the devices, was examined with a photoluminescence (PL) technique. The experimental results showed that the thickness of the oxide layer can significantly influence the synaptic and resistive switching properties of the devices.

Could mesangial C3 deposition be an independent prognostic marker in immunoglobulin A nephropathy?

BACKGROUND: Immunoglobulin A nephropathy (IgAN) is a common primary glomerulonephropathy. There is evidence that mesangial C3 deposition plays a role in the development of the disease. The aim of this study was to examine the effect of C3 deposition on the prognosis of IgAN patients. METHOD: The study included 1135 patients with biopsy-confirmed IgAN from the database of the Turkish Nephrology Association Glomerular Diseases Working Group (TSN-GOLD). Patients were excluded from the study if they were aged < 18 or > 75 years or if C3 staining had not been performed in the immunofluorescent analysis. C3 deposition was defined as an immunofluorescence intensity of C3 ≥ 2 + within the mesangium. The primary endpoints were the development of end-stage renal disease, a 30% decrease in glomerular filtration rate compared to the basal value or an elevation in proteinuria to a nephrotic level (3.5 gr/day). RESULTS: Mesangial C3 deposition was observed in 603 (53.1%) patients. No statistically significant difference was found at baseline between the groups with and without mesangial C3 deposition, as for age, sex, BMI, proteinuria level, or the presence of hypertension. In the follow-up period with a mean duration of 78 months, no significant difference was found between the two groups regarding the primary endpoints (p = 0.43). A significant correlation between C3 deposition and segmental glomerulosclerosis (S1) according to the Oxford MEST-C classification was found (p = 0.001). CONCLUSION: Although a correlation was observed between mesangial C3 deposition and the S1 MEST-C classification, mesangial C3 deposition was not a prognostic factor in IgAN.

Demographic, clinical and laboratory characteristics of adult-onset minimal change disease in Turkey: Turkish Society of Nephrology-Glomerular Diseases (TSN-GOLD) Working Group.

PURPOSE: In our study, diagnostic and demographic characteristics of patients diagnosed with minimal change disease (MCD) by biopsy, clinical and laboratory findings in our country were investigated. METHODS: Data were obtained from the Turkish Society of Nephrology Glomerular Diseases (TSN-GOLD) Working Group database. Demographic characteristics, indications for biopsy, diagnosis of the glomerular diseases, comorbidities, laboratory and biopsy findings of all patients were recorded. The data presented are cross-sectional and includes application data for the biopsy period. RESULTS: Of 3875 patients, 233 patients with MCD (median age 35.0 years) were included in the study, which constitutes 6.0% of the total glomerulonephritis database. Renal biopsy was performed in 196 (84.1%) patients due to nephrotic syndrome. Median serum creatinine was 0.7 (0.6-1.0) mg/dl, mean eGFR was 104 ± 33 ml/min/1.73 m2 and median proteinuria 6000 mg/day. The number of patients under the age of 40 years was 139 (59.7%) (Group A), and the number of patients aged 40 years and over was 94 (40.3%) (Group B). Compared to Group A, global sclerotic glomeruli (24 vs. 43, p < 0.001) interstitial inflammation (15 vs. 34, p < 0.001), interstitial fibrosis (20 vs. 31, p = 0.001, vascular changes (10 vs. 25, p < 0.001) and tubular atrophy (18 vs. 30, p < 0.001) were found to be significantly higher in Group B. There was no difference in immunofluorescent staining properties between the two groups. CONCLUSION: Our data are generally compatible with the literature. Chronic histopathological changes were more common in patients aged 40 years and older than younger patients. Studies investigating the effects of these different features on renal survival are needed.

Can mean platelet volume predicts renal outcome in acute on chronic kidney disease?

INTRODUCTION: This study aimed to investigate the role of mean platelet volume (MPV) in predicting renal outcome in acute kidney injury (AKI) developing on pre-existing chronic kidney disease (CKD). METHODS: The patients whose first hemodialysis program was initiated in our center were divided into two groups as those who were taken to the scheduled dialysis program after discharge and those who were not dialysis-dependent. Groups were compared in terms of demographic characteristics, and laboratory parameters including MPV. RESULTS: A total of 288 patients were included in the study (scheduled dialysis = 162 patients, nondialysis dependent = 126 patients). High MPV was found to be an independent risk factor for scheduled dialysis programs in multivariable analyses (OR [95% CI]: 90.9 [6.3-1313.6], p: 0.001). CONCLUSION: CKD patients with high MPV were more likely to be included in scheduled dialysis programs after an AKI attack. MPV is found to be an independent risk factor and a reliable predictor for a scheduled dialysis program.

Relationship of Gamma-glutamyl Transferase Levels at Diagnosis with Clinicopathological Features in idiopathic IgA Nephropathy.

OBJECTIVE: To compare clinicopathologic features of idiopathic IgA nephropathy in terms of serum gamma-glutamyl transferase (GGT) levels. STUDY DESIGN: Cross-sectional study. PLACE AND DURATION OF STUDY: Department of Nephrology and Department of Pathology, Afyonkarahisar Health Sciences University, Afyonkarahisar, Turkey, from January 2010 to January 2021. METHODOLOGY: All patients diagnosed with IgA nephropathy were retrospectively evaluated. Patients were divided into quartiles of gamma-glutamyl transferase. Clinical and pathological features were compared between the groups. RESULTS: A total of 69 patients with idiopathic IgA nephropathy were analysed. The GGT quartiles consisted of Q1(GGT ≤14 U/L) in 18 patients, Q2(GGT = 14.01-20 U/L) in 17 patients, Q3(GGT = 20.1-35 U/L) in 18 patients, and Q4(GGT >35 U/L) in 16 patients. The rates of mesangial cellularity, segmental glomerulosclerosis, and tubular atrophy were found to be significantly different among GGT groups (p= 0.024, p= 0.048, and p<0.001 respectively). Serum albumin and 24-hours proteinuria were also significantly different between groups (p<0.001). CONCLUSION: Gamma-glutamyl transferase may play a role in some clinical and pathological features of IgA nephropathy. KEY WORDS: Gamma-glutamyl transferase, IgA nephropathy, Proteinuria, Serum albumin, Mesangial Cellularity, Segmental glomerulosclerosis, Tubular atrophy.

Clinical and pathologic features of primary membranous nephropathy in Turkey: a multicenter study by the Turkish Society of Nephrology Glomerular Diseases Working Group.

BACKGROUND: We aimed to evaluate the features of primary membranous nephropathy (MNP) in Turkish people. METHODS: This is a retrospective analysis of patients with biopsy-proven primary MNP. We obtained the data collected between 2009 and 2019 in the primary glomerulonephritis registry of the Turkish Society of Nephrology Glomerular Diseases Study Group (TSN-GOLD). Patients with a secondary cause for MNP were excluded. Clinical, demographic, laboratory, and histopathological findings were analyzed. RESULTS: A total of 995 patients with primary MNP were included in the analyses. Males constituted the majority (58.8%). The mean age was 48.4 ± 13.9 years. The most common presentation was the presence of nephrotic syndrome (81.7%) and sub nephrotic proteinuria (10.3%). Microscopic hematuria was detected in one-third of patients. The median estimated glomerular filtration rate (eGFR) was 100.6 mL/min/1.73 m2 (IQR, 75.4-116.3), and median proteinuria was 6000 mg/d (IQR, 3656-9457). Serum C3 and C4 complement levels were decreased in 3.7 and 1.7% of patients, respectively. Twenty-four (2.4%) patients had glomerular crescents in their kidney biopsy samples. Basal membrane thickening was detected in 93.8% of cases under light microscopy. Mesangial proliferation and interstitial inflammation were evident in 32.8 and 55.9% of the patients, respectively. The most commonly detected depositions were IgG (93%), C3 complement (68.8%), and kappa and lambda immunoglobulin light chains (70%). Although renal functions were normal at presentation, vascular, interstitial, and glomerular findings were more prominent on biopsy in hypertensive patients. No significant effect of BMI on biopsy findings was observed. CONCLUSIONS: Despite some atypical findings, the main features of primary MNP in Turkey were similar to the published literature. This is the largest MNP study to date conducted in Turkish people.

The Longitudinal Evolution of Post-COVID-19 Outcomes Among Hemodialysis Patients in Turkey.

Introduction: Hemodialysis (HD) patients have increased risk for short-term adverse outcomes of COVID-19. However, complications and survival at the post-COVID-19 period have not been published extensively. Methods: We conducted a national, multicenter observational study that included adult maintenance HD patients recovered from confirmed COVID-19. A control HD group without COVID-19 was selected from patients in the same center. We investigated the characteristics and outcomes in the follow-up of HD patients and compare them with the non-COVID-19 group. Results: A total of 1223 patients (635 patients in COVID-19 group, 588 patients in non-COVID-19 group) from 47 centers were included in the study. The patients' baseline and HD characteristics were almost similar. The 28th-day mortality and mortality between 28th day and 90th day were higher in the COVID-19 group than non-COVID-19 group (19 [3.0%] patients vs. none [0%]; 15 [2.4%] patients vs. 4 [0.7%] patients, respectively). The presence of respiratory symptoms, rehospitalization, need for home oxygen therapy, lower respiratory tract infection, and arteriovenous (AV) fistula thrombosis was significantly higher in the COVID-19 group in both the first 28 days and between 28 and 90 days. In the multivariable analysis, age (odds ratio [OR] [95% CI]: 1.029 [1.004-1.056]), group (COVID-19 group vs. non-COVID-19 group) (OR [95% CI]: 7.258 [2.538-20.751]), and vascular access type (tunneled catheter/AV fistula) (OR [95% CI]: 2.512 [1.249-5.051]) were found as independent parameters related to 90-day mortality. Conclusion: In the post-COVID-19 period, maintenance HD patients who have had COVID-19 have increased rehospitalization, respiratory problems, vascular access problems, and high mortality compared with the non-COVID-19 HD patients.

Pregnancy and its outcomes in hemodialysis patients in Turkey.

BACKGROUND/AIM: This study aimed to investigate pregnancy frequency and evaluate the factors affecting live births in hemodialysis (HD) patients. MATERIALS AND METHODS: Female HD patients whose pregnancy was retrospectively reported between January 1, 2014, and December 31, 2019. The duration of HD, primary disease, whether the pregnancy resulted in abortion, stillbirth, or live birth, whether the HD duration was prolonged after diagnosing the pregnancy and whether it accompanied preeclampsia were recorded. RESULTS: In this study, we reached 9038 HD female patients? data in the study. A total of 235 pregnancies were detected in 145 patients. The mean age was 35.42 (35 ± 7.4) years. The mean age at first gestation was 30.8 ± 6.5 years. The average birth week was 32 (28 - 36) weeks. 53.8% (no = 78) of the patients had live birth, 51.7% (no = 70) had at least one abortion in the first 20 weeks, and 13.1% (no = 19) had at least one stillbirth after 20 weeks. The rate of patients' increased numbers of dialysis sessions during pregnancy was 71.7%. The abortion rate was 22.4% in those with increased HD sessions, whereas 79.3% in those not increased HD sessions (p < 0.001). Live birth frequency was 67.2% in the increased HD sessions group and 3.4% in those who did not differ in HD sessions (p < 0.001). CONCLUSION: For the first time, we reported pregnancy outcomes in HD female patients, covering all regions of Turkey. It has been observed that; increasing the number of HD sessions in dialysis patients will decrease fetal and maternal complications and increase live birth rates.

Demographic, clinical and laboratory characteristics of rapidly progressive glomerulonephritis in Turkey: Turkish Society of Nephrology-Glomerular Diseases (TSN-GOLD) Working Group.

BACKGROUND: In our study, diagnostic and demographic characteristics of patients diagnosed with RPGN by biopsy, clinical and laboratory findings in our country were investigated. METHODS: Data were obtained from the Turkish Society of Nephrology Glomerular Diseases (TSN-GOLD) Working Group database. Demographic characteristics, indications for biopsy, diagnosis of the glomerular diseases, comorbidities, laboratory and biopsy findings of all patients were recorded. According to their types, RPGN patients were classified as type 1 (anti-GBM related), type 2 (immuncomplex related) and type 3 (pauci-immune). RESULTS: Of 3875 patients, 200 patients with RPGN (mean age 47.9 ± 16.7 years) were included in the study which constitutes 5.2% of the total glomerulonephritis database. Renal biopsy was performed in 147 (73.5%) patients due to nephritic syndrome. ANCA positivity was found in 121 (60.5%) patients. Type 1 RPGN was detected in 11 (5.5%), type 2 RPGN in 42 (21%) and type 3 RPGN in 147 (73.5%) patients. Median serum creatinine was 3.4 (1.9-5.7) mg/dl, glomerular filtration rate was 18 (10-37) ml/min/1.73m2 and proteinuria 2100 (1229-3526) mg/day. The number of crescentic glomeruli ratio was ratio 52.7%. It was observed that urea and creatinine increased and calcium and hemoglobin decreased with increasing crescentic glomerular ratio. CONCLUSIONS: Our data are generally compatible with the literature. Advanced chronic histopathological findings were prominent in the biopsy of 21 patients. Early biopsy should be performed to confirm the diagnosis of RPGN and to avoid unnecessary intensive immunosuppressive therapy. In addition to the treatments applied, detailed data, including patient and renal survival, are needed.

Are preoperative serum CA15-3 levels different in breast cancer subgroups?

PURPOSE: Breast cancer classifies to 4 major subgroups according to immunohistochemistry staining features as Luminal A, Luminal B, human epidermal growth factor receptor 2 overexpression, and Triple Negative. Cancer Antigen15-3 (CA15-3) is used as a tumor marker in breast cancer while its value in early stage and in breast cancer subgroups is still controversial. In this study, we aimed to investigate that whether it is or not differences of the serum preoperative CA15-3 levels in early breast cancer subgroups. METHODS: We retrospectively investigated medical records of 751 breast cancer patients who admitted to Afyon Kocatepe University Department of Medical Oncology between January 2010 and December 2016. Total 361 patients were included in this study. The cut off value of Ki-67 was used as 20 to distinguish between Luminal A from Luminal B subgroups. Cutoff values of CA15-3 were evaluated as 25U/mL. RESULTS: CA15-3 levels were not significantly different according to clinical features. Molecular subgroups were similar in CA15-3 levels (P = 0.666). Elevated levels of CA15-3 ≥ 25 U/mL were found 34 patients (20.5%) in Luminal A, 15 patients (28.3%) in Luminal B1, 15 patients (20.3%) in Luminal B2, 7 patients (25%) in human epidermal growth factor receptor 2 overexpressed and 9 patients (22.5%) in triple negative groups. CONCLUSION: There was no relationship preoperative CA15-3 levels and breast cancer subgroups.

Assesment of the patients presenting with severe anemia to the emergency internal medicine clinic.

OBJECTIVE: Etiological evaluation of the patients who were hospitalized with the diagnosis of severe anemia (Hb<7 gr/dl) in the emergency internal medicine clinic between January and July, 2013. METHODS: In this study, 112 patients who were hospitalized in Dr. Lutfi Kirdar Kartal Education and Research Hospital emergency internal medicine clinic with severe anemia between January and July 2013 were retrospectively analyzed. Patients' initial complaints, underlying causes of their anemia and prognosis of the patients were evaluated. RESULTS: The etiology of anemia was iron deficiency in 60 (53.6%), chronic kidney failure in 16 (14.2%), hematologic malignancies in 12 (10.7%), liver cirrhosis in 12 (10.7%) and other non-malignant hematologic disorders in 4 (3.6%) patients. CONCLUSION: The most common cause of anemia in patients who apply to emergency internal medicine clinic with severe anemia is iron deficiency. The most common complaints on admission are subjective ones such as weakness, fatigue and lassitude. Chronic disease anemia does not cause severe anemia as much as iron deficiency.