Measurement system for ultraviolet channel modeling and communications.

There has been an increasing interest in ultraviolet (UV) communications as a promising technology for non-line-of-sight (NLOS) networking by exploiting atmospheric scattering at UV wavelengths that enables a unique NLOS UV communication channel. While there has been significant theoretical and simulation-based investigation of the UV channel characteristics, there is limited work in terms of experimental research and validation of the analytical models. In this paper, we present a flexible experimental system for precise UV channel and communications measurements. Specifically, a transceiver system is developed that consists of a gimbal, UV light-emitting-diode array, and photomultiplier tube detector, node synchronization, and LabVIEW-based data acquisition subsystems. Novel techniques to precisely characterize the UV LED array radiation pattern, absolute transmit power, and field of view of the detector are also presented. The utility of the developed system is then demonstrated by performing a variety of experiments including UV channel model validation and steering optimization for UV communication links where the results were in very good agreement with theory and simulation.

Optimization of ultraviolet communication links based on finite difference stochastic approximation.

The ultraviolet communication (UV) channel has been shown to have unique features that could be exploited for covert ground-to-ground communications in complex non-line-of-sight (NLOS) scenarios. A key challenge is the determination of optimal configuration of pointing directions of the UV nodes in unknown NLOS environments to maximize the link performance. In this paper, we proposed a novel steering optimization approach based on Finite Difference Stochastic Approximation (FDSA) to simultaneously optimize the transmitter (Tx) and receiver (Rx) pointing directions without any knowledge about the locations and relative orientations of the two nodes. We perform parametric analysis using Monte Carlo channel simulations to investigate and select appropriate key algorithmic parameters and analyze the performance of the proposed algorithm. We also carry out experimentation using our custom designed UV Tx and Rx gimbal systems and demonstrate the utility and efficiency of the proposed steering optimization approach and show that the received photon count can be increased significantly.

Analysis of the low-probability-of-detection characteristics of ultraviolet communications.

Deep ultraviolet wavelengths have been proposed for low-probability-of-detection (LPD) communications, particularly for non-line-of-sight (NLOS) links, because of the increased atmospheric absorption at these wavelengths. Motivated by this favorable feature, we develop a modeling framework to quantitatively study the LPD characteristics of ultraviolet communications (UVC). We then demonstrate the application of our modeling framework by considering various friendly and adversarial system configurations and quantifying the proposed LPD metric (the range at which an adversary can detect communications that uses the minimum power needed to meet given communications performance requirements), as well as investigating the sensitivity of the analysis to various scenario parameters. The results demonstrate the potential for this modeling and analysis approach to provide key insights into the design and operation of LPD NLOS UVC systems.

3D evaluation of tooth crown size in unilateral cleft lip and palate patients.

AIM: The aim of this retrospective study is to evaluate and compare the 3-dimensional (3D) crown sizes of the left and right sides of upper and lower dental arches in patients with unilateral cleft lip and palate (UCLP). MATERIALS AND METHODS: Dental casts of 94 patients all in permanent dentition were included in this study. Dental casts were divided into three groups as 36 casts with unilateral left cleft lip and palate (ULCLP), 18 casts with unilateral right cleft lip and palate (URCLP), and 40 casts without cleft (control). Mesiodistal (MD), buccolingual (BL), and gingiva incisal (GI) values of each tooth were measured by scanning the dental models with a high-precision optical 3D scanner. Paired t-test and independent t-test were used for statistical analysis. RESULTS: U1 MD, U6 MD (P = 0.001) and BL (P = 0.01), L3 GI (P = 0.05) were greater in UCLP patients on the non-cleft side while U1 GI, L1 BL, L5 MD (P = 0.001), L4 MD, and BL (P = 0.01) values were found to be greater on the cleft side. Comparison of the cleft-sides and the control group showed that MD, BL, and GI dimensions of teeth on the cleft sides were generally found to be smaller, excluding the UR7 GI values for URCLP group (P = 0.05). CONCLUSION: In the measurements of teeth size, reliable and repeatable results were acquired through 3D software. Tooth size asymmetries can occur non-syndromic UCLP patients in both jaws. MD, BL, and GI dimensions of teeth are mostly found to be smaller in patients with CLP.

The impact of sarcopenia on morbidity and long-term survival among patients with peritoneal metastases of colorectal origin treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy: a 10-year longitudinal analysis of a single-center experience.

BACKGROUND: The aim of this study was to evaluate the prognostic value of preoperative sarcopenia with regard to postoperative morbidity and long-term survival in patients with peritoneal metastasis from colorectal cancer treated with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). METHODS: A longitudinal cohort study was conducted on patients with peritoneal metastases of colorectal origin treated with CRS-HIPEC between 2008 and 2018. Data on patient demographics, body mass index, operative characteristics, perioperative morbidity and survivorship status and oncological follow-up were obtained from the hospital registry. Sarcopenia was assessed using preoperative computed tomography (CT) findings. RESULTS: Sixty-five patients [mean (SD) age: 54.4 (13.4) years, 64.6% females] were included in the study. Sarcopenia was evident in 30.8% of patients, while mortality rate was 66.2% with median survival time of 33.6 months. Presence of sarcopenia was associated with older age (59.6 (9.2) vs. 52.1 (14.4) years, p = 0.038), higher likelihood of morbidity (70.0% vs. 35.6%, p = 0.015) and mortality (90.0% vs. 55.6%, p = 0.010) and shorter survival time (17.7 vs. 37.9 months, p = 0.005). Cox regression analysis revealed that the presence of sarcopenia (HR 2.245, 95% CI 0.996-5.067, p = 0.050) was a significant predictor of increased likelihood of mortality. CONCLUSIONS: Preoperative sarcopenia is an independent prognostic factor of postoperative morbidity and shorter survival in CRC peritoneal metastasis patients treated with CRS-HIPEC. Our findings support the importance of preoperative screening for sarcopenia as part of preoperative risk assessment for better selection of CRS-HIPEC candidates or treatment modifications in CRC patients with peritoneal metastasis.

Preventing parastomal hernia with modified stapled mesh stoma reinforcement technique (SMART) in patients who underwent surgery for rectal cancer: a case-control study.

PURPOSE: Parastomal hernia is a frequent complication of an abdominal wall stoma. Surgical repairs have high complication and recurrence rates. Several different techniques have been suggested to prevent parastomal hernia during stoma creation. The aim of the present case-control study was to evaluate the efficacy of modified Stapled Mesh stomA Reinforcement Technique (SMART) for prevention of parastomal hernia compared with conventional colostomy formation in patients who underwent open or laparoscopic rectal resection and end colostomy for cancer. METHODS AND MATERIALS: Between January 2014 and May 2016, all consecutive patients who underwent open or laparoscopic resection and end colostomy for primary or recurrent rectal cancer were identified from a prospectively collected database. Since January 2014, one surgeon in our team has routinely offered modified SMART procedure to all patients who are candidates for permanent terminal colostomy. In the SMART group patients, while creating an end colostomy, we placed a standard polypropylene mesh in the retromuscular position, fixed and cut the mesh by firing a 31- or 33-mm-diameter circular stapler and constructed the stoma. In the control group, a stoma was created conventionally by a longitudinal or transverse incision of the rectus abdominis sheath sufficiently large for the colon to pass through. RESULTS: Twenty-nine patients underwent parastomal hernia prophylaxis with modified SMART and 38 patients underwent end-colostomy formation without prophylaxis (control group). Groups were similar in terms of age, sex and underlying conditions predisposing to herniation. Median follow-up time is 27 (range 12-41) months. Nineteen patients (28.4%) developed parastomal herniation. In the SMART group, 4 patients (13.8%) developed parastomal herniation which is significantly lower than the control group in which 15 patients (39.5%) developed parastomal herniation (p = 0.029). We did not observe mesh infection, stenosis, erosion or fistulation in the SMART group. One patient in the control group underwent surgical correction of stoma stricture, another patient underwent surgery for stoma prolapse and four patients underwent surgery for parastomal herniation. CONCLUSION: New systemic reviews and meta-analysis support parastomal hernia prevention with the use of a prophylactic mesh. Until more evidence is available, prophylactic mesh should be routinely offered to all patients undergoing permanent stoma formation. SMART is easy to use, safe and effective for paracolostomy hernia prophylaxis.

Alternative medicine usage among solid tumour patients receiving chemotherapy.

We aimed to investigate complementary or alternative medicine (CAM) usage and knowledge levels of chemotherapy (CT) receiving cancer patients. Questionnaires about CAM usage and knowledge levels of the patients were completed. A total of 289 patients were included. Median age was 58 (min-max: 21-89) years. Sixty-two of 289 patients (22%) received CAM. Fifty-two patients (18%) thought CAM was beneficial and 237 of them (82%) thought that it was harmful. Sixty-one of them (98%) received CAM orally. Majority of CAMs used were herbal substances. Twenty-eight of the patients (45%) used CAM due to belief of natural products strengthen their body, 16 of them (26%) used CAM due to insistence of their relatives, 8 patients (13%) used CAM with thought of their CT did not benefit and 10 patients (16%) received CAM as a supportive treatment. Thirty-seven patients (60%) received CAM concomitant with CT. Thirty-two patients (52%) did not inform their clinicians while using CAM. Twenty-one (34%) and 45 (73%) of patients had no opinion or knowledge about effects and side effects of CAM they used respectively. Nearly half of the patients did not inform their clinicians about CAM they used. Knowledge level of patients used CAM was poor.

Effects of chito-oligosaccharides and L-carnitine supplementation in diets for Japanese quails on performance, carcass traits and some blood parameters / Efeitos da chito-oligossacarídeos e suplementação de L-carnitina em dietas para codornas Japonesas sobre o desempenho, características de carcaça e de alguns parâmetros sanguíneos

The aim of this study was to determine effects of dietary supplementation with chitosanoligosaccharides (COS) and L-carnitine, individually or dually, on growth performance, carcass traits and some blood serum parameters in quails. A total of 192, four days old, Japanese quail chicks were allotted four groups, each of which included four replicates (12 birds per replicate). The groups received the same basal diet supplemented with 0 (Control), 150mg/kg chitosanoligosaccharides (COS), 150mg/kg L-carnitine (Carnitine), and 150 mg/kg chitosanoligosaccharides+150 mg/kg L-carnitine (COS+Car.) during the starter (1 to 21 days) and a grower (22 to 42 days) period. The feeding trial shoved that COS, L-carnitine and COS+L-carnitine had no significant effect on live weight, live weight gain, feed consumption and feed conversion. Supplementation with COS+L-carnitine induced higher leg ratio from than that of the Control. There were no differences on serum albumin, total protein, glucose and total cholesterol concentrations. It is concluded that due to the obtained higher leg ratio from COS+Car. group, after analysis of the profit and loss, if is economically profitable, chitosanoligosaccharides+L-carnitine could be added quail diets.

O estudo objetivou determinar os efeitos da suplementação com chito-oligossacarídeos (COS) e L-carnitina, individualmente ou em conjunto, sobre o desempenho, características de carcaça e alguns parâmetros sanguíneos em codornas. Um total de 192 codornas japonesas, com quatro dias de vida foi separado em quatro grupos, cada grupo com quatro repetições (12 aves por repetição). Os grupos receberam a mesma dieta basal suplementada com 0 (Controle), 150mg/kg chito-oligossacarídeos (COS), 150mg/kg L-carnitina (Carnitina), e 150mg/kg chito-oligossacarídeos +150 mg/kg L-carnitina (COS+Car.) durante o período inicial (1 a 21 dias) e de crescimento (22 a 42 dias). A fase de alimentação mostrou que COS, L-carnitina e COS+L-carnitina não tiveram efeito significativo no peso vivo, ganho de peso vivo, consumo de alimento e conversão de alimento. A suplementação com COS+L-carnitina induziu proporção de perna maior que o Controle. Não houve diferenças na concentração de albumina sérica, proteína total, glicose e colesterol total. Conclui-se que devido à proporção maior de perna obtida para o grupo COS+Car., após análise de perda e ganho, se for economicamente viável chito-oligossacarídeos+L-carnitina pode ser adicionado à dieta de codornas.

Transfusion-related acute lung injury following coronary artery bypass graft surgery.

Blood transfusion is sometimes a necessary procedure during or following coronary artery bypass graft (CABG) surgery. However, transfusion-related acute lung injury (TRALI)/possible TRALI is a rare and fatal complication and characterized by acute hypoxemia and non-cardiogenic pulmonary edema that occurs within 6 hours following a transfusion. Anti-leukocyte antibodies or, possibly, other bioactive substances cause inflammation and capillary endothelial destruction in susceptible recipients' lungs. Prompt diagnosis and mechanical ventilatory support are important. A successful treatment of two male patients following CABG surgery, compatible with TRALI/possible TRALI, is presented here.

Breast cancer in octogenarian women: clinical characteristics and outcome.

PURPOSE: Breast cancer incidence increases in the elderly but data on treatment and outcomes of elderly patients is limited. We assessed the clinicopathological features and outcomes of our patients with breast cancer aged ≥80 years in comparison with their younger postmenopausal counterparts. METHODS: The records of 83 patients diagnosed with breast cancer after the age of 80 (group 1) between 2003 and 2011 in 4 different centers were retrospectively evaluated and the clinicopathological features and outcomes were assessed in comparison with a control group (group 2) of 249 patients aged between 60-70 years. RESULTS: Median ages at diagnosis were 82 years (range 80-95) and 64 years (range 60-70) for group 1 and group 2, respectively. The incidence of invasive cancers other than ductal or lobular type was higher in group 1 than in group 2 (20 vs 8%; p=0.0177rpar;. More patients in group 1 had Charlson Comorbidty scores ≥1 than those in group 2 (49 vs 36%; p=0.011). Patients in group 1 had more conservative operations and less axillary node dissections (ALND) and they received chemotherapy, trastuzumab or radiotherapy less frequently compared to their younger counterparts in group 2. Median follow up period was 36 months (range 1-178) in group 1 and 24 months (range 12-217) in group 2. Five-year disease free survival (DFS) was 53.7 and 75.9) (p=0.005), 5-year overall survival (OS) was 61.9% and 80.47percnt; in group 1 and group 2 (p=0.001), respectively. Advanced stage (stage IV vs stage I, II, III, p=0.051) and cerbB2 positivity (p<0.001) were found to be associated with shorter DFS in patients ≥80 years of age. CONCLUSION: Although the majority of patients were undertreated in our study according to the current guidelines, mortality rates were quite low. Different biology of the disease in the elderly might explain this difference.

Promising therapeutic options in triple-negative breast cancer.

Triple-negative breast cancer (TNBC) has a greater risk of recurrence despite more aggressive therapy even in lowrisk category. TNBC is high grade, hormone receptor and HER-2 negative, it exhibits a high level of Ki-67 staining and expresses the epithelial growth factor receptor (EGFR). Because of its expression profile, treatment options are limited to cytotoxic chemotherapy. Molecular defects that give rise to BRCA1-associated breast cancer also occur in TNBC. Thus, the combination of poly-(ADP-ribose)-polymerase (PARP) inhibitors with drugs that cause DNA breakages, such as alkylating agents and topoisomerase I inhibitors, could theoretically potentiate the efficacy of each drug in patients with TNBC. Clinical trials with various targeted approaches alone or in combination with different chemotherapeutic agents are currently underway. In this review, current and future treatment approaches in TNBC with novel targeted agents are discussed.

Pure mucinous carcinoma of the breast: a single center experience.

PURPOSE: Mucinous breast carcinoma is rare subtype of breast cancer. Histopathologically, it is classified into two forms, pure and mixed type. It recurs late, metastasis to axillary lymph nodes is less common and is more hormone receptor positive. We herein present the data of our patients with pure mucinous breast cancer (PMBC) treated in our institution. METHODS: Among 1211 breast cancer patients with breast cancer diagnosed and treated in Hacettepe University Institute of Oncology, 20 patients (1.6%) with PMBC (defined as having mucinous component of more than 90%) were identified. Patient demographics, tumor characteristics and patient outcomes were assessed retrospectively. RESULTS: The median age at diagnosis was 52.5 years (range 27-80). The majority of the patients presented with stage II disease (n=15; 75%). One of 20 patients recurred with bone metastasis 50 months after diagnosis. Median follow-up was 39 months (range 3-137). Estrogen receptors (ER) were positive in 16 (80%) patients and HER-2 positive in one (5%). Twenty-five percent of the patients had positive axillary nodes. CONCLUSION: PMBC is a rare entity with favorable prognosis. Lymph node metastasis is rarely seen even in large -sized tumors.

Malignancies after rituximab treatment: just coincidence or more?

PURPOSE: Rituximab has been successfully used in the treatment of B-cell non-Hodgkin's lymphoma (NHL) and some autoimmune diseases nearly for a decade. Several other malignancies and CD20-negative lymphomas have been reported in the literature after rituximab treatment. We aimed to investigate whether there is an association between rituximab treatment and the development of second malignancies. METHODS: A detailed search in English language literature on reports about rituximab treatment and secondary malignancies was made through Medline. The papers were reviewed and the cases were summarized according to secondary tumor types, intervals between rituximab treatment and second malignancy occurrence, indications for rituximab treatment and cytotoxic chemotherapy administration. RESULTS: There were 26 previously reported cases of CD20-negative lymphoma and solid tumors after rituximab treatment. The median age of these cases was 62 years (range 34-80). The median time period from the initiation of rituximab treatment to diagnosis of second malignancies was 5 months (range 1-40). The most frequently reported solid tumors were skin tumors (squamous cell carcinoma and Merkel cell carcinoma) (n=7; 27%), CD20-negative lymphomas (n=5; 20%), Kaposi sarcoma (n=4; 15%), and others (n=10; 38%). CONCLUSION: Association between rituximab and subsequent development of second malignancies might be a coincidence. However, we suggest close monitoring for second malignancies, particularly skin tumors, in patients treated with rituximab. This issue should be evaluated in further studies.

Glucose tolerance of premenopausal women after menopause due to surgical removal of ovaries.

OBJECTIVE: To evaluate the influence of the abrupt withdrawal of ovarian function on glucose tolerance by studying premenopausal women before and after oophorectomy. METHODS: Thirty premenopausal women who needed hysterectomy for benign reasons volunteered for the study in our hospital in Istanbul, Turkey. An oral glucose tolerance test (OGTT) was performed before surgery and 3, 6 and 12 months after surgery. Fasting glucose, fasting insulin levels and insulin/glucose indexes, HOMA indexes, insulin and glucose levels were measured during OGTT. RESULTS: The mean fasting and 2-h glucose levels of the women did not change significantly during the 12 months of follow-up. However, the glucose levels during the glucose tolerance tests changed significantly after surgery (p<0.05). Insulin responses to the glucose tolerance test also increased significantly (p<0.005). Insulin/glucose indexes were significantly higher after surgery (p<0.005). Type 2 diabetes mellitus was detected in five women and impaired glucose tolerance was detected in 12 of the 30 patients after surgery in the 12-month period. CONCLUSION: The impairment of carbohydrate metabolism due to an abrupt decrease in natural estrogen levels should be considered before removing the ovaries during hysterectomy in premenopausal patients.

Secondary hematological malignancies after treatment of non-metastatic breast cancer.

PURPOSE: To determine the frequency of secondary hematological malignancies in non-metastatic breast cancer (BC) patients who received adjuvant chemotherapy and radiotherapy. METHODS: Data of BC patients followed at Hacettepe University Institute of Oncology, Department of Medical Oncology between 2004 and 2010 were retrospectively analysed. RESULTS: There were 1,475 BC patients followed between 2004 and 2010 at our department; 1,319 (89.4%) of them had not metastatic disease. One thousand, one hundred eighty three (89.7%) early-stage BC patients received at least one treatment modality (radiotherapy and/or chemotherapy). The number of patients receiving only chemotherapy or only radiotherapy were 228 (17.3%) and 117 (8.9%), respectively. Eleven (1%) out of 1,066 BC patients receiving adjuvant/neoadjuvant chemotherapy were also treated with granulocyte colony stimulating factor (G-CSF). The frequency of secondary hematological malignancies among adjuvant or neoadjuvant chemotherapy BC patients was 0.56% (6/1,066); it was 0.59% (7/1,183) among radiotherapy and/or chemotherapy treated non-metastatic BC patients. Five patients developed acute myeloid leukemia (AML); 3 of them were AML-FAB M3 and 2 could not be subclassified. The 6th patient had multiple myeloma and the 7th had diffuse large B cell lymphoma (DLBCL). However, the latter did not receive cytotoxic chemotherapy for BC. CONCLUSION: Treatment-associated secondary hematological malignancies, especially myeloid leukemias, are a growing problem due to high prevalence of BC and the dismal outcome of secondary leukemias. Further studies are needed to determine the risk for other hematological malignancies, possible responsible agents, and mechanisms.

Trace elements and toxic heavy metals play a role in Buerger disease and atherosclerotic peripheral arterial occlusive disease.

AIM: The aim of the present study was to define the roles of trace elements and toxic heavy metals in Buerger disease and atherosclerotic peripheral arterial occlusive disease (PAOD). METHODS: Seventy-five subjects who were identical in demographic charecteristics were selected for the study; 25 with Buerger disease, 25 with PAOD, 25 healthy volunteers. Serum selenium (Se), zinc (Zn), copper (Cu), iron (Fe),whole blood cadmium (Cd) and lead (Pb), erythrocyte glutathione (GSH), erythrocyte glutathione peroxidase (GSH-Px), erythrocyte and plasma malondialdehyde (MDA) levels were measured. RESULTS: Serum Se and Zn levels were significantly low in patients with Buerger disease compared to patients with PAOD and controls (P<0.001 and P<0.001 respectively). Serum levels of Fe and Zn were also significantly low in patients with PAOD compared to controls (p<0.001 and p<0.05 respectively). In contrast, Cu and Pb levels in Buerger disease group were significantly high compared to PAOD and control groups (P<0.001 and P<0.001 respectively). Erythrocyte GSH and GSH-Px levels were significantly lower in patients with Buerger disease compared to patients with PAOD and controls (P<0.001 and P<0.001 respectively), while erythrocyte and plasma MDA levels were significantly higher (P<0.001 and P<0.001 respectively). CONCLUSION: It can be concluded that the levels of trace elments and toxic heavy metals and oxidative stress influence the disease process in Buerger disease more than PAOD.