Integrated segmented IQ-modulator for orthogonal sampling and multi-level high-bandwidth signal generation.

Photonic-assisted signal processing of high-bandwidth signals emerges as a solution for challenges encountered in electronic-based processing. Here we present a concept for a compact, photonic-assisted digital-to-analog converter (DAC) and optical IQ-modulator in one single integrated device based on two innovative concepts: a segmented Mach-Zehnder modulator and orthogonal sampling. For electrically driving the modulator, only a single radio frequency oscillator and no pulse source or electrical DAC are required. The presented and simulated proof-of-concept device with six segments can generate a multi-level and high-bandwidth signal from low-bandwidth electronic drivers; e.g., we show the generation of a 120 Gbps data rate, 16-quadrature amplitude modulation (16-QAM, 30 Gbaud) signal solely based on low-bandwidth (5 GHz) non-return-to-zero (NRZ) signals. Integrated on a silicon photonic platform, the device provides fixable speed and bandwidth operations, positioning it as a viable solution for diverse communication systems.

A comprehensive review on the application of semiconducting materials in the degradation of effluents and water splitting.

In this comprehensive review article, we delve into the critical intersection of environmental science and materials science. The introduction sets the stage by emphasizing the global water shortage crisis and the dire consequences of untreated effluents on ecosystems and human health. As we progress into the second section, we embark on an intricate exploration of piezoelectric and photocatalytic principles, illuminating their significance in wastewater treatment and sustainable energy production. The heart of our review is dedicated to a detailed analysis of the detrimental impacts of effluents on human health, underscoring the urgency of effective treatment methods. We dissected three key materials in the realm of piezo-photocatalysis: ZnO-based materials, BaTiO3-based materials, and bismuth-doped materials. Each material is scrutinized for its unique properties and applications in the removal of pollutants from wastewater, offering a comprehensive understanding of their potential to address this critical issue. Furthermore, our exploration extends to the realm of hydrogen production, where we discuss various types of hydrogen and the role of piezo-photocatalysis in generating clean and sustainable hydrogen. By illuminating the synergistic potential of these advanced materials and technologies, we pave the way for innovative solutions to the pressing challenges of water pollution and renewable energy production. This review article not only serves as a valuable resource for researchers and scholars in the fields of material science and environmental engineering but also underscores the pivotal role of interdisciplinary approaches in addressing complex global issues.

Real-time reconfigurable on-chip photonic frequency decoder.

A group-delay-unit-based integrated silicon photonic integrated circuit (PIC) is employed as a reconfigurable analog radio frequency decoder, which provides a real-time temporal and spectral analysis of any arbitrary multi-tone signal in the micro- and mm-wave range. The circuit is based on cascaded Mach-Zehnder interferometer embedded silicon microring resonators as variable delay units. The temporal decoding of the multi-tone input signal is demonstrated by tuning the signal with respect to the ring resonator delay and resonance. A one-to-one conformal time-to-frequency mapping provides real-time spectral decoding of the signal under test without additional digital signal processing. The idea is validated by several experimental results with single-tone and two-tone input signals in a compact, low-power, silicon PIC. The proposed real-time temporal analog frequency decoder may be very intriguing for high-speed, low-latency wireless applications, such as autonomous driving and 6G.

Perspectives on modes of labour and delivery after different modalities of surgery for bowel endometriosis.

Bowel or intestinal endometriosis is estimated to affect 5-37% of women with deep infiltrative endometriosis (DIE), especially in the rectum and recto-sigmoid junction. However, there are no current guidelines or consensus regarding safest mode of delivery in pregnant women after different surgical interventions for bowel/intestinal endometriosis. From October 2019 to February 2020, we conducted an online survey of members of the British Society for Gynaecological Endoscopy (BSGE). These included questions on what gynaecologist members would recommend as modes of delivery in women who had different surgical modalities for bowel endometriosis, and the particular factors that influence such recommendations. Analysis of data was performed using SPSS for Windows (V9) software package. One hundred and two members of BSGE completed the survey (61.76% of BSGE gynaecologist members). Only 30.39% of respondents counsel women, pre-operatively, about possible effects of surgical treatment of bowel endometriosis on their subsequent mode of delivery. Our survey highlights wide variation in practice that currently exists. Around 70% of clinicians are not counselling patients regarding delivery options pre-surgery despite almost one-third recommending planned caesarean section if the vagina is opened. Further studies are required to stratify the risk factors for such patients when attempting vaginal delivery or caesarean section.IMPACT STATEMENTWhat is already known on this subject? Treatment of colorectal endometriosis consists of rectal shaving, discoid resection or segmental colorectal resection. However, the relationship between different surgical modalities for bowel endometriosis and the subsequent safe mode of labour and delivery remains unclear.What do the results of this study add? No study has been published that specifically looked at the particular course and outcome of labour and delivery after each of these bowel surgeries; rectal shaving, disc excision, or segmental colorectal resection. Our study highlights the wide variations in practice that currently exists. Despite around 70% of clinicians not counselling women regarding delivery options pre-surgery, almost one-third would recommend a planned caesarean section if the vagina is opened.What are the implications of these findings for clinical practice and/or further research? This study suggests that risk factors should be stratified for such patients when attempting a vaginal delivery or undergoing a caesarean section. Guidance from the ESGE and/or BSGE would be useful to aid in the counselling and informed consent of such patients.

A mapping study of ensemble classification methods in lung cancer decision support systems.

Achieving a high level of classification accuracy in medical datasets is a capital need for researchers to provide effective decision systems to assist doctors in work. In many domains of artificial intelligence, ensemble classification methods are able to improve the performance of single classifiers. This paper reports the state of the art of ensemble classification methods in lung cancer detection. We have performed a systematic mapping study to identify the most interesting papers concerning this topic. A total of 65 papers published between 2000 and 2018 were selected after an automatic search in four digital libraries and a careful selection process. As a result, it was observed that diagnosis was the task most commonly studied; homogeneous ensembles and decision trees were the most frequently adopted for constructing ensembles; and the majority voting rule was the predominant combination rule. Few studies considered the parameter tuning of the techniques used. These findings open several perspectives for researchers to enhance lung cancer research by addressing the identified gaps, such as investigating different classification methods, proposing other heterogeneous ensemble methods, and using new combination rules. Graphical abstract Main features of the mapping study performed in ensemble classification methods applied on lung cancer decision support systems.

Reviewing ensemble classification methods in breast cancer.

CONTEXT: Ensemble methods consist of combining more than one single technique to solve the same task. This approach was designed to overcome the weaknesses of single techniques and consolidate their strengths. Ensemble methods are now widely used to carry out prediction tasks (e.g. classification and regression) in several fields, including that of bioinformatics. Researchers have particularly begun to employ ensemble techniques to improve research into breast cancer, as this is the most frequent type of cancer and accounts for most of the deaths among women. OBJECTIVE AND METHOD: The goal of this study is to analyse the state of the art in ensemble classification methods when applied to breast cancer as regards 9 aspects: publication venues, medical tasks tackled, empirical and research types adopted, types of ensembles proposed, single techniques used to construct the ensembles, validation framework adopted to evaluate the proposed ensembles, tools used to build the ensembles, and optimization methods used for the single techniques. This paper was undertaken as a systematic mapping study. RESULTS: A total of 193 papers that were published from the year 2000 onwards, were selected from four online databases: IEEE Xplore, ACM digital library, Scopus and PubMed. This study found that of the six medical tasks that exist, the diagnosis medical task was that most frequently researched, and that the experiment-based empirical type and evaluation-based research type were the most dominant approaches adopted in the selected studies. The homogeneous type was that most widely used to perform the classification task. With regard to single techniques, this mapping study found that decision trees, support vector machines and artificial neural networks were those most frequently adopted to build ensemble classifiers. In the case of the evaluation framework, the Wisconsin Breast Cancer dataset was the most frequently used by researchers to perform their experiments, while the most noticeable validation method was k-fold cross-validation. Several tools are available to perform experiments related to ensemble classification methods, such as Weka and R Software. Few researchers took into account the optimisation of the single technique of which their proposed ensemble was composed, while the grid search method was that most frequently adopted to tune the parameter settings of a single classifier. CONCLUSION: This paper reports an in-depth study of the application of ensemble methods as regards breast cancer. Our results show that there are several gaps and issues and we, therefore, provide researchers in the field of breast cancer research with recommendations. Moreover, after analysing the papers found in this systematic mapping study, we discovered that the majority report positive results concerning the accuracy of ensemble classifiers when compared to the single classifiers. In order to aggregate the evidence reported in literature, it will, therefore, be necessary to perform a systematic literature review and meta-analysis in which an in-depth analysis could be conducted so as to confirm the superiority of ensemble classifiers over the classical techniques.

Using ensemble classification methods in lung cancer disease.

This paper presents an overview of the use of ensemble classification methods in the lung cancer disease. An analysis is carried out according to seven aspects: publication trends, channels and venues; medical tasks tackled; ensemble types proposed; single techniques used to construct the ensemble methods; rules used to draw the output of the ensemble; datasets used to build and evaluate the ensemble methods; and tools used. The application of ensemble methods in lung cancer disease started in 2003. The diagnosis task was the most tackled one by researchers. Furthermore, the homogeneous ensembles were the most frequent in the literature, and decision tree techniques were the most adopted ones for constructing ensembles. Several datasets related to the lung cancer disease were used to build and assess the ensemble methods. The most used tool was Weka. To conclude, some recommendations for future research are: tackle the medical tasks not investigated in the literature by means of ensemble methods; investigate other classification methods; propose other heterogeneous ensemble methods; and use other combination rules.

Homogeneous and heterogeneous ensemble classification methods in diabetes disease: a review.

This paper explores the use of ensemble classification methods in the context of the diabetes disease. An analysis was carried out that formulates and answers seven research questions: publication trends, channels and venues; medical tasks undertaken; ensemble types proposed; single techniques used to construct the ensemble methods; rules used to draw the output of the ensemble; datasets used to build and evaluate the ensemble methods; and tools used. A total of 107 papers were chosen after a study selection process. Ensemble methods were applied to diabetes in 2003 for the first time. All medical tasks related to the diabetes disease were investigated, and the diagnosis task was the most frequently addressed activity by means of ensemble methods. The homogeneous ensembles were the most common in the literature. Moreover, decision trees and support vector machines were the most used techniques to build homogeneous and heterogeneous ensembles, respectively. The most frequently found combiner was the majority voting rule. Our findings suggest that ensemble classification methods yield better accuracy than single classifiers. This statement, however, requires an aggregation of the evidence reported in the literature by means of a systematic literature review.

Safety of a novel modular cage for transforaminal lumbar interbody fusion - clinical cohort study in 20 patients with degenerative disc disease.

INTRODUCTION: Transforaminal lumbar interbody fusion (TLIF) is used to reconstruct disc height and reduce degenerative deformity in spinal fusion. Patients with osteoporosis are at high risk of TLIF cage subsidence; possibly due to the relatively small footprint compared to anterior interbody devices. Recently, modular TLIF cage with an integral rail and slot system was developed to reduce cage subsidence and allow early rehabilitation. OBJECTIVE: To study the safety of a modular TLIF device in patients with degenerative disc disorders (DDD) with regard to surgical complications, non-union, and subsidence. METHODS: Patients with DDD treated with a modular TLIF cage (Polyetheretherketone (PEEK), VTI interfuse S) were analysed retrospectively with one-year follow-up. Lumbar sagittal parameters were collected preoperatively, postoperatively and at one year follow-up. Cage subsidence, fusion rate, screw loosening and proportion of endplate coverage were assessed in computed tomography scan. RESULTS: 20 patients (age 66 ± 10 years, 65% female, BMI 28 ± 5 kg/m2) with a total of 37 fusion levels were included. 15 patients had degenerative spondylosis and 5 patients had degenerative scoliosis. The cages covered >60% of the vertebral body diameters. Lumbar lordosis angle and segmental disc angle increased from 45.2 ± 14.5 and 7.3 ± 3.6 to 52.7 ± 9.1 and 10.5 ± 3.5 (p = 0.029 and 0.0002) postoperatively for each parameter respectively without loss of correction at one year follow up. One case of deep postoperative infection occurred (5%). No cage subsidence occurred. No non-union or screw loosening occurred. CONCLUSIONS: The modular TLIF cage was safe with regard to subsidence and union-rate. It restored and maintained lumbar lordosis angle, segmental disc angle and disc height, which can be attributed to the large footprint of this modular cage.

Early oocyte denudation does not compromise ICSI cycle outcome: a large retrospective cohort study.

This retrospective cohort study of 2051 consecutive fresh non-donor intracytoplasmic sperm injection (ICSI) cycles investigated whether time from oocyte retrieval to denudation, precisely measured and recorded by an operator-independent automated radiofrequency-based system, affected cycle outcome. ICSI cycles were divided into two groups: group I (denudation within <2 h of oocyte retrieval, n = 1118) and group II (denudation 2-5 h after oocyte retrieval, n = 933). Univariate analysis by two-sample t-test or Mann-Whitney test was used, as appropriate. Both groups were comparable with regards to mean number of oocytes retrieved and fertilized normally after ICSI. The mean number of embryos transferred and surplus embryos cryopreserved at the blastocyst stage were similar. There was no significant difference in fertilization, embryo implantation, pregnancy, clinical pregnancy or live birth rates between the groups. Analysis of group I ICSI outcome after subdivision into immediate (up to 30 min) and early (31-119 min) denudation showed no statistically significant differences between the two subgroups. In conclusion, early oocyte denudation within <2 h after retrieval does not appear to compromise ICSI cycle outcome, permitting more efficiency and flexibility in scheduling laboratory workload. As this was a retrospective observational study, further prospective studies are required to confirm the findings.

Take-home experience of overseas doctors at the end of their two years training placements in the International Doctors Training Programme in Obstetrics and Gynaecology in the United Kingdom: A questionnaire-based study.

This was a questionnaire-based study of overseas doctors, who came to the United Kingdom through the International Doctors Training Programme (IDTP) of Obstetrics and Gynaecology during the period of 2009-2012. The study was conducted at the end of their two-years training placement to find out what went well, what did not go well, where problems were encountered, and how they could have been avoided. We traced 48 overseas doctors, 35 (73%) responded to our questionnaire. Only 30% (9) felt that less than 50% of their expectations were met during their training period, 73.3% (22) of them received adequate help and support from their supervisors and 83.3% (25) would recommend IDTP to their colleagues. In conclusion, identification of the educational needs of international trainees, establishing a framework for their effective supervision and streamlining their training programme, in collaboration with the Royal College, regional deaneries and hosting hospitals are essential pre-requisites for overseas doctors to get the most out of their training.

Is endometrial ablation protective against endometrial cancer? A retrospective observational study.

STUDY OBJECTIVES: Endometrial ablation has been increasingly used over the last 30 years to manage patients with dysfunctional uterine bleeding. Of primary concern, however, is the potential of the procedure to mask the presence or delay the diagnosis of endometrial cancer. The aim of this study is to assess the long-term effects of endometrial ablation and its association with the development of endometrial cancer. METHODS: This is a retrospective observational study that was conducted at Bradford Teaching Hospitals in the United Kingdom. The study included all women who had different types of endometrial ablative procedures in the period of January 1994 to December 2011. Analysis of the data was performed using SPSS for windows (V9) software package. RESULTS: Over 18 years period, 1521 women had endometrial ablative procedures for dysfunctional uterine bleeding. During their long-term follow-up, none of the women developed endometrial cancer later in life. This incidence is much lower than the lifetime risk of endometrial cancer in the general population (RR 0.0135; 95 % CI 0.0007-0.2801; P = 0.0054). CONCLUSION: To our knowledge, this is the largest study to examine the long-term incidence of endometrial cancer in women who had endometrial ablative procedures. It shows that the development of endometrial cancer does not seem to be associated with endometrial ablative procedures.

Diagnostic and therapeutic dilemmas of cervical ectopic pregnancy.

IMPORTANCE: Cervical pregnancy is a rare variety of ectopic pregnancy. The etiology is obscure. Its diagnosis may be difficult, and its management has enormously changed during the last 10 years. Unfortunately, the most effective, fertility-sparing treatment is still unclear until now. OBJECTIVES: The aim of this study was to explore the safety and efficacy of different treatment modalities of cervical pregnancy. EVIDENCE ACQUISITION: A comprehensive systematic review of the literature was performed using the electronic databases MEDLINE and PubMed, using key words cervical, ectopic, and pregnancy, between January 2005 and June 2013. We included all case reports and case series reporting on cervical ectopic pregnancy. RESULTS: A total of 252 cases of cervical ectopic pregnancy were analyzed. Eighty-eight cases (34.9%) had medical treatment, 69 cases (27.5%) had surgical treatment, and 95 cases (37.6%) had combined medical and surgical treatment. Various conservative treatment regimens have been introduced to preserve fertility in young women, with methotrexate being one of the most widely used and effective drugs. CONCLUSIONS AND RELEVANCE: A high index of suspicion, combined with meticulous review of clinical and radiological findings, is essential to make an accurate diagnosis of cervical pregnancy. The success of conservative treatment depends mainly on early diagnosis. Such cases would be best managed at specialist tertiary referral centers and preferably, where available, Early Pregnancy Assessment Units, whether medical, surgical, or combined treatment modalities were attempted.

Evaluation of three different surgical approaches in repairing paravaginal support defects: a comparative trial.

OBJECTIVES: Paravaginal defects have been shown to account for 60-80% of anterior compartment prolapse and its repair offers the chance of a more effective cure of such defect. There is no good evidence to suggest the superiority of a particular route of paravaginal repair. The objective of this study was to evaluate the effectiveness of abdominal (APVR), vaginal (VPVR) and laparoscopic (LPVR) approaches in the repair of such defects. STUDY DESIGN: This is a prospective comparative study of patients, referred over a 2-year period, with symptomatic stage II­IV anterior compartment prolapse due to paravaginal support defects. Patients were assessed subjectively by direct verbal questioning, and objectively, using POP-Q system for staging, at 1, 6 and 12 months postoperatively. Analysis of data was performed using SPSS for Windows (V9) software package. RESULTS: Forty-five patients were recruited to the study. There was no significant difference in the subjective and objective outcomes of APVR (n = 20) and VPVR (n = 20) groups. The laparoscopic approach had to be abandoned after five patients only, as the degree of improvement in prolapse stage was less than in the other two approaches. CONCLUSION: The effectiveness of paravaginal repair procedure is similar whether the abdominal or vaginal approaches were adopted in patients with anterior compartment prolapse due to paravaginal support defects. In our experience, the laparoscopic approach was associated with the least favourable outcome.