bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of Preoperative Evaluation with the Pathological Report in Intraductal Papillary Mucinous Neoplasms: A Single-Center Experience
Authors: Djordjevic Vladimir , Grubor Nikica , Kovac Jelena Djokic , Micev Marjan , Milic Natasa , Knezevic Djordje , Gregoric Pavle , Lausevic Zeljko , Kerkez Mirko , Knezevic Srbislav , Radenkovic Dejan
Published: February 2021

The key to the successful management of pancreatic cystic neoplasm (PCN), among which intraductal papillary mucinous neoplasm (IPMN) is the one with the highest risk of advanced neoplasia in resected patients, is a careful combination of clinical, radiological, and histopathological findings. This study aims to perform the comparison of a preoperative evaluation with pathological reports in IPMN and further, to evaluate and compare the diagnostic performance of European evidence-based guidelines on pancreatic cystic neoplasms (EEBGPCN) and Fukuoka Consensus guidelines (FCG). We analyzed 106 consecutive patients diagnosed with different types of PCN, among whom 68 had IPMN diagnosis, at the Clinical Center of Serbia. All the patients diagnosed with IPMNs were stratified concerning the presence of the absolute and relative indications according to EEBGPCN and high-risk stigmata and worrisome features according to FCG. Final histopathology revealed that IPMNs patients were further divided into malignant (50 patients) and benign (18 patients) groups, according to the pathological findings. The preoperative prediction of malignancy according to EEBGPCN criteria was higher than 70% with high sensitivity of at least one absolute or relative indication for resection. The diagnostic performance of FCG was shown as comparable to EEBGPCN. Nevertheless, the value of false-positive rate for surgical resection showed that in some cases, overtreating patients or treating them too early cannot be prevented. A multidisciplinary approach is essential to adequately select patients for the resection considering at the same time both the risks of surgery and malignancy.
Word Recognition and Frequency Selectivity in Cochlear Implant Simulation: Effect of Channel Interaction
Authors: Cucis Pierre-Antoine , Berger-Vachon Christian , Thaï-Van Hung , Hermann Ruben , Gallego Stéphane , Truy Eric
Published: February 2021

In cochlear implants (CI), spread of neural excitation may produce channel interaction. Channel interaction disturbs the spectral resolution and, among other factors, seems to impair speech recognition, especially in noise. In this study, two tests were performed with 20 adult normal-hearing (NH) subjects under different vocoded simulations. First, there was a measurement of word recognition in noise while varying the number of selected channels (4, 8, 12 or 16 maxima out of 20) and the degree of simulated channel interaction (“Low”, “Medium” and “High”). Then, there was an evaluation of spectral resolution function of the degree of simulated channel interaction, reflected by the sharpness (Q10dB) of psychophysical tuning curves (PTCs). The results showed a significant effect of the simulated channel interaction on word recognition but did not find an effect of the number of selected channels. The intelligibility decreased significantly for the highest degree of channel interaction. Similarly, the highest simulated channel interaction impaired significantly the Q10dB. Additionally, a strong intra-individual correlation between frequency selectivity and word recognition in noise was observed. Lastly, the individual changes in frequency selectivity were positively correlated with the changes in word recognition when the degree of interaction went from “Low” to “High”. To conclude, the degradation seen for the highest degree of channel interaction suggests a threshold effect on frequency selectivity and word recognition. The correlation between frequency selectivity and intelligibility in noise supports the hypothesis that PTCs Q10dB can account for word recognition in certain conditions. Moreover, the individual variations of performances observed among subjects suggest that channel interaction does not have the same effect on each individual. Finally, these results highlight the importance of taking into account subjects’ individuality and to evaluate channel interaction through the speech processor.
The Role of Circulating Tumor Cells in Chemoresistant Metastatic Breast Cancer
Authors: Lisencu Lorena Alexandra , Bonci Eduard-Alexandru , Irimie Alexandru , Balacescu Ovidiu , Lisencu Cosmin
Published: February 2021

Breast cancer is the most frequent form of cancer among women and is one of the leading causes of death. Two routes of the metastatic process have been described: linear and parallel progression. A key factor is represented by circulating tumor cells (CTCs). CTCs detach from the primary tumor or develop from cancer stem cells (CSCs) that undergo epithelial-to-mesenchymal transition (EMT). CTCs migrate to the distant site where the reverse process occurs and a new tumor arises. One of the key problems of metastatic disease is chemoresistance, which leads to treatment failure and, eventually, death. The aim of this review is to present up-to-date data regarding the role of CTCs in chemoresistance in metastatic breast cancer (MBC) patients. A search in Cochrane Library and MEDLINE databases was performed. A total of 125 articles were identified. The results of the final 12 eligible studies revealed that CTCs having stem cell features and those with mesenchymal features are aggressive subtypes of cells that survive chemotherapy, being responsible for chemoresistance and thus for disease progression in MBC patients. The hemodynamic shear stress, alongside dynamic changes among CTCs during the disease, is also an important disease progression factor.
The Impact of Patient Age ≥80 Years on Postoperative Outcomes and Treatment Costs Following Pancreatic Surgery
Authors: Andreou Andreas , Aeschbacher Pauline , Candinas Daniel , Gloor Beat
Published: February 2021

As life expectancy is increasing, elderly patients are evaluated more frequently for resection of benign or malignant pancreatic lesions. However, the impact of age on postoperative morbidity, mortality, and treatment costs in octogenarian patients (≥80 years) undergoing major pancreatic surgery needs further investigation. The clinicopathological data of patients who underwent pancreatic surgery between January 2015 and March 2019 in a major hepatopancreatobiliary center in Switzerland were assessed. Postoperative outcomes and hospital costs of octogenarians and younger patients were compared in univariate and multivariate regression analysis. During the study period, 346 patients underwent pancreatic resection. Pancreatoduodenectomy, distal pancreatectomy, total pancreatectomy, and other procedures were performed in 54%, 20%, 13%, and 13% of patients, respectively. The major postoperative morbidity rate and postoperative mortality rate were 25% and 3.5%, respectively. A total of 39 patients (11%) were ≥80 years old, and 307 patients were <80 years old. The majority of octogenarians suffered from ductal adenocarcinoma, whereas among younger patients, other indications for a pancreatic resection were predominant (ductal adenocarcinoma 64% vs. 41%, p = 0.006). Age ≥80 was associated with more frequent postoperative medical (pulmonary, cardiovascular) and surgical (high-grade pancreatic fistula, postoperative hemorrhage) complications. Postoperative mortality was significantly higher in octogenarians (15.4% vs. 2%, p < 0.0001). This finding may be explained by the higher rate of type C pancreatic fistula (13% vs. 5%), resulting more frequently in postoperative hemorrhage (18% vs. 5%, p = 0.002) among patients ≥80 years old. In the multivariate logistic regression analysis, patient age ≥80 years predicted postoperative mortality independently of the tumor entity and surgical technique (p = 0.013, OR 6.71, 95% CI [1.5–30.3]). Increased major postoperative morbidity was responsible for lower cost recovery in octogenarians (94% vs. 102%, p = 0.046). In conclusion, patient age ≥80 years is associated with increased postoperative medical and surgical morbidity after major pancreatic surgery leading to lower cost recovery and a lower chance for successful resuscitation in patients requiring revisional surgery for postoperative hemorrhage and/or pancreatic fistula. In octogenarian patients suffering from pancreatic tumors, careful selection, and thorough prehabilitation is crucial to achieve the best postoperative and long-term oncologic outcomes.
Shear Wave Elastography in Patients with Primary and Secondary Hyperparathyroidism
Authors: Amzar Daniela , Cotoi Laura , Sporea Ioan , Timar Bogdan , Schiller Oana , Schiller Adalbert , Borlea Andreea , Pop Nicusor Gheorghe , Stoian Dana
Published: February 2021

Objectives: In this study, we aim to determine the elastographic characteristics of both primary and secondary hyperparathyroidism using shear wave elastography. We also aim to evaluate the elastographic differences between them, as well as the differences between the parathyroid, thyroid, and muscle tissue, in order to better identify a cutoff value for the parathyroid tissue. Methods: In this prospective study, we examined a total of 68 patients with hyperparathyroidism, divided into two groups; one group consisted of 27 patients with primary hyperparathyroidism and the other group consisted of 41 selected patients with confirmed secondary hyperparathyroidism. The elasticity index (EI) was determined in the parathyroid, thyroid, and muscle tissue. The determined values were compared to better identify the parathyroid tissue. Results: The median value of mean SWE values measured for parathyroid adenomas from primary hyperparathyroidism was 4.86 kPa. For secondary hyperparathyroidism, the median value of mean SWE was 6.96 KPa. The median (range) presurgical values for parathormone (PTH) and calcium were 762.80 pg/mL (190, 1243) and 9.40 mg/dL (8.825, 10.20), respectively. We identified significant elastographic differences between the two groups (p < 0.001), which remained significant after adjusting elastographic measures to the nonparametric parameters, such as the parathormone value and vitamin D (p < 0.001). The cutoff values found for parathyroid adenoma were 5.96 kPa and for parathyroid tissue 9.58 kPa. Conclusions: Shear wave elastography is a helpful tool for identifying the parathyroid tissue, in both cases of primary and secondary hyperparathyroidism, as there are significant differences between the parathyroid, thyroid, and muscle tissue. We found a global cutoff value for the parathyroid tissue of 9.58 kPa, but we must keep in mind that there are significant elastographic differences between cutoffs for primary and secondary hyperparathyroidism.
Ovulatory-Based FET Cycles May Achieve Higher Pregnancy Rates in the General Population and among Anovulatory Women
Authors: Aslih Nardin , Dorzia Dore , Atzmon Yuval , Estrada Daniella , Ellenbogen Adrian , Bilgory Asaf , Shalom-Paz Einat
Published: February 2021

This study evaluated which endometrial preparation protocol in frozen embryo transfer (FET) cycles provides the best results for polycystic ovarian syndrome (PCOS) patients and the general population. This retrospective study of 634 FET cycles was conducted 2016–2018. Cycles were divided into Group A: Artificial endometrial preparations for FET (aFET; n = 348), Group B: Ovulatory cycle (n = 286) to compare two methods of endometrial preparation for FET. Artificial endometrial preparation with exogenous estrogen and progesterone versus natural ovulation cycles, modified natural cycles using hCG for the final triggering and letrozole-induced ovulation with hCG. Anovulatory patients were analyzed separately. Anovulatory PCOS patients had significantly higher pregnancy rates with letrozole treatment compared with aFET cycles (44% vs. 22.5%; p = 0.044). For the entire cohort, ovulatory cycles and aFET were similar in terms of patient characteristics, demographics, infertility causes, treatment protocols and number of embryos transferred. Although the mean ESHRE score of the transferred embryos was higher in the aFET group, we found higher clinical pregnancy rate in the ovulatory cycle FET (41.3% vs. 27.3%, p < 0.0001). A better pregnancy rate was found after ovulatory cycle FET. In the ovulatory cycles, the outcome of letrozole-induced and non-induced cycles were comparable. PCOS patients, as well as the general population, may benefit from ovulation induced FET cycles, with significantly better outcomes in FET in ovulatory cycles.
The Long-Term Effectiveness of Omalizumab in Adult Patients with Severe Allergic Asthma: Continuous Treatment Versus Boosting Treatment
Authors: Huang Wei-Chang , Fu Pin-Kuei , Chan Ming-Cheng , Chin Chun-Shih , Huang Wen-Nan , Lai Kuo-Lung , Wang Jiun-Long , Hung Wei-Ting , Wu Yi-Da , Hsieh Chia-Wei , Wu Ming-Feng , Chen Yi-Hsing , Hsu Jeng-Yuan
Published: February 2021

The implications of boosting Omalizumab treatment (OT) in patients with severe allergic asthma (SAA) remain unclear. The study aimed to explore and compare the 12-month effectiveness between continuous, at least 10-month OT (continuation group) and four-month boost of Omalizumab (boost group) in adult patients with SAA. In this retrospective cohort study, clinical data were collected for further analysis. Of all participants (n = 124), a significant reduction in annual exacerbations (baseline = 0.8 ± 1.5, follow-up = 0.5 ± 1.0, p = 0.047 *) and improvement in small airway ventilation as evaluated by forced expiratory flow at 25–75% (baseline = 55.1 ± 11.1%, follow-up = 59.4 ± 8.4%, p < 0.001 *) were found in the continuation group (n = 110). By contrast, the boost group (n = 14) had significantly increased annual exacerbations (baseline = 0.7 ± 1.4, follow-up = 2.9 ± 3.6, p = 0.031 *) and impaired small airway function (baseline = 55.3 ± 12.9, follow-up = 52.1 ± 12.5, p = 0.026 *). Furthermore, the continuation group rather than the boost group had significant decreases in the frequency of oral corticosteroid (OCS) use as controllers (baseline = 32.7%, follow-up = 20.0%, p = 0.047 *; baseline = 50.0%, follow-up = 21.4%, p = 0.237, respectively) and OCS maintenance dose (mg/month) (baseline = 85.9 ± 180.8, follow-up = 45.8 ± 106.6, p = 0.020 *; baseline = 171.4 ± 221.5, follow-up = 50.0 ± 104.3, p = 0.064, respectively), and increases in asthma control test scores (baseline = 16.0 ± 3.0, follow-up = 19.8 ± 4.4, p < 0.001 *; baseline = 14.6 ± 3.8, follow-up = 19.7 ± 4.7, p = 0.050, respectively). Continuous OT would be beneficial for adult patients with SAA, while boost of Omalizumab would worsen their long-term outcomes.
Embryological Development and Topographic Anatomy of Pelvic Compartments—Surgical Relevance for Pelvic Lymphonodectomy
Authors: Bayer Andreas , Heinze Tillmann , Alkatout Ibrahim , Osmonov Daniar , Stelzner Sigmar , Wedel Thilo
Published: February 2021

Background: The oncological outcome of surgery for the treatment of pelvic malignancies can be improved by performing pelvic lymphonodectomy. However, the extent and regions of lymph node harvest are debated and require profound knowledge of anatomy in order to avoid collateral damage. Methods: The embryological development and topographic anatomy of pelvic compartments in relation to pelvic lymphonodectomy for rectal, uterine, and prostate cancer are reviewed. Based on pre-dissected anatomical specimens, lymph node regions and drainage routes of the posterior and urogenital pelvic compartments are described in both genders. Anatomical landmarks are highlighted to identify structures at risk of injury during pelvic lymphonodectomy. Results: The ontogenesis of urogenital and anorectal compartments and their lymphatic supply are key factors for adequate lymphonodectomy, and have led to compartment-based surgical resection strategies. However, pelvic lymphonodectomy bears the risk of injury to somatic and autonomic nerves, vessels, and organs, depending on the regions and extent of surgery. Conclusion: Embryologically defined, compartment-based resection of pelvic malignancies and their lymphatic drainage routes are based on clearly delineated anatomical landmarks, which permit template-oriented pelvic lymphonodectomy. Comprehensive knowledge of pelvic anatomy, the exchange of surgical concepts between specialties, and minimally invasive techniques will optimize pelvic lymphonodectomy and reduce complications.
Negative Impact of Elevated DNA Fragmentation and Human Papillomavirus (HPV) Presence in Sperm on the Outcome of Intra-Uterine Insemination (IUI)
Authors: Depuydt Christophe , Donders Gilbert , Verstraete Ludo , Beert Johan , Salembier Geert , Bosmans Eugene , Dhont Nathalie , Kerkhofs Carmen , Ombelet Willem
Published: February 2021

We wanted to determine the sperm DNA fragmentation index (DFI) cutoff for clinical pregnancies in women receiving intra-uterine insemination (IUI) with this sperm and to assess the contribution of Human Papillomavirus (HPV) infection on sperm DNA damage and its impact on clinical pregnancies. Prospective non-interventional multi-center study with 161 infertile couples going through 209 cycles of IUI in hospital fertility centers in Flanders, Belgium. Measurement of DFI and HPV DNA with type specific quantitative PCRs (HPV 6, 11, 16, 18, 31, 33, 35, 39, 45, 51, 52, 53, 56, 58, 59, 66 and 68) in sperm before its use in IUI. Clinical pregnancy (CP) rate was used as the outcome to analyze the impact on fertility outcome and to calculated the clinical cutoff value for DFI. A DFI criterion value of 26% was obtained by receiver operating characteristic (ROC) curve analysis. Couples with a male DFI > 26% had significantly less CPs than couples with DFI below 26% (OR 0.0326; 95% CI 0.0019 to 0.5400; p = 0.017). In sperm, HPV prevalence was 14.8%/IUI cycle. Sperm samples containing HPV had a significantly higher DFI compared to HPV negative sperm samples (29.8% vs. 20.9%; p = 0.011). When HPV-virions were present in sperm, no clinical pregnancies were observed. More than 1 in 5 of samples with normal semen parameters (17/78; 21.8%) had an elevated DFI or was HPV positive. Sperm DFI is a robust predictor of clinical pregnancies in women receiving IUI with this sperm. When DFI exceeds 26%, clinical pregnancies are less likely and in vitro fertilization techniques should be considered.
Cardiometabolism as an Interlocking Puzzle between the Healthy and Diseased Heart: New Frontiers in Therapeutic Applications
Authors: Pasqua Teresa , Rocca Carmine , Giglio Anita , Angelone Tommaso
Published: February 2021

Cardiac metabolism represents a crucial and essential connecting bridge between the healthy and diseased heart. The cardiac muscle, which may be considered an omnivore organ with regard to the energy substrate utilization, under physiological conditions mainly draws energy by fatty acids oxidation. Within cardiomyocytes and their mitochondria, through well-concerted enzymatic reactions, substrates converge on the production of ATP, the basic chemical energy that cardiac muscle converts into mechanical energy, i.e., contraction. When a perturbation of homeostasis occurs, such as an ischemic event, the heart is forced to switch its fatty acid-based metabolism to the carbohydrate utilization as a protective mechanism that allows the maintenance of its key role within the whole organism. Consequently, the flexibility of the cardiac metabolic networks deeply influences the ability of the heart to respond, by adapting to pathophysiological changes. The aim of the present review is to summarize the main metabolic changes detectable in the heart under acute and chronic cardiac pathologies, analyzing possible therapeutic targets to be used. On this basis, cardiometabolism can be described as a crucial mechanism in keeping the physiological structure and function of the heart; furthermore, it can be considered a promising goal for future pharmacological agents able to appropriately modulate the rate-limiting steps of heart metabolic pathways.
Gynecologic Malignancies in Children and Adolescents: How Common is the Uncommon?
Authors: Wohlmuth Christoph , Wohlmuth-Wieser Iris
Published: February 2021

The aim of this study is to assess the projected incidence and prognostic indicators of gynecologic malignancies in the pediatric population. In this population-based retrospective cohort study, girls ≤18 years with ovarian, uterine, cervical, vaginal and vulvar malignancies diagnosed between 2000 and 2016 were identified from the Surveillance, Epidemiology and End Results (SEER)-18 registry. The Kaplan–Meier method was used to analyze overall survival (OS). The age-adjusted annual incidence of gynecologic malignancies was 6.7 per 1,000,000 females, with neoplasms of the ovary accounting for 87.5%, vagina 4.5%, cervix 3.9%, uterus 2.5% and vulva 1.6% of all gynecologic malignancies. Malignant germ-cell tumors represented the most common ovarian neoplasm, with an increased incidence in children from 5–18 years. Although certain subtypes were associated with advanced disease stages, the 10-year OS rate was 96.0%. Sarcomas accounted for the majority of vaginal, cervical, uterine and vulvar malignancies. The majority of vaginal neoplasms were observed in girls between 0–4 years, and the 10-year OS rate was 86.1%. Overall, gynecologic malignancies accounted for 4.2% of all malignancies in girls aged 0–18 years and the histologic subtypes and prognosis differed significantly from patients in older age groups.
Estimation of the Periodontal Inflamed Surface Area by Simple Oral Examination
Authors: Nomura Yoshiaki , Morozumi Toshiya , Numabe Yukihiro , Ogata Yorimasa , Nakayama Yohei , Sugaya Tsutomu , Nakamura Toshiaki , Sato Soh , Takashiba Shogo , Sekino Satoshi , Yoshinari Nobuo , Hanada Nobuhiro , Sugano Naoyuki , Fukuda Mitsuo , Minabe Masato , Umeda Makoto , Tabeta Koichi , Takahashi Keiso , Noguchi Kazuyuki , Kobayashi Hiroaki , Takai Hideki , Nishimura Fusanori , Suzuki Fumihiko , Kakuta Erika , Yoshimura Atsutoshi , Saito Atsushi , Nakagawa Taneaki
Published: February 2021

The periodontal inflamed surface area (PISA) is a useful index for clinical and epidemiological assessments, since it can represent the inflammation status of patients in one contentious variable. However, calculation of the PISA is difficult, requiring six point probing depth measurements with or without bleeding on probing on 28 teeth, followed by data input in a calculation program. More simple methods are essential for screening periodontal disease or in epidemiological studies. In this study, we tried to establish a convenient partial examination method to estimate PISA. Cross-sectional data of 254 subjects who completed active periodontal therapy were analyzed. Teeth that represent the PISA value were selected by an item response theory approach. The maxillary second molar, first premolar, and lateral incisor and the mandibular second molar and lateral incisor were selected. The sum of the PISAs of these teeth was significantly correlated with the patient’s PISA (R2 = 0.938). More simply, the sum of the maximum values of probing pocket depth with bleeding for these teeth were also significantly correlated with the patient’s PISA (R2 = 0.6457). The simple model presented in this study may be useful to estimate PISA.
Percutaneous Occlusion of the Left Atrial Appendage with Thrombus Irresponsive to Antithrombotic Therapy
Authors: Kaczmarek Krzysztof , Cygankiewicz Iwona , Streb Witold , Plaksej Rafal , Jakubowski Piotr , Kalarus Zbigniew , Ptaszynski Pawel , Wranicz Jerzy Krzysztof , Babicz-Sadowska Anna , Markiewicz Agata , Grygier Marek
Published: February 2021

We analyzed clinical experience with percutaneous closure of instances of left atrial appendage with thrombus (LAAT) irresponsive to antithrombotic therapy in patients treated in three high-volume cardiology centers. Clinical and procedural data regarding consecutive patients who underwent percutaneous left atrial appendage closure (PLAAC) due to LAAT were retrospectively analyzed. The study population consisted of 17 patients (11 men; 68 ± 14 years; CHA2DS2VASC 4.7 ± 1.9; HASBLED 3 (0–5)) with LAAT confirmed by transesophageal echocardiography, and included 5 patients with mechanical heart valves. Most of the patients (94.1%) received anticoagulation therapy before PLAAC. All LAATs were located in distal portions of the appendage and occupied less than 30% of its volume. Occluding-device implantation was successful in 17 patients; in one, a residual leak was disclosed. Appropriate positioning of occluders required more than 1 attempt in 6 individuals (35.3%); in 3 others (17.6%), the subjects’ devices had contact with thrombi. No procedural complications were noted. Midterm follow-up (median: 10 months) revealed no procedure-related complications or clinically diagnosed thromboembolism. Transesophageal echocardiography (TEE) performed after six months revealed device-related thrombus in one patient. We concluded that LAAT irresponsive to antithrombotic therapy might be effectively treated with PLAAC, even in patients with mechanical-valve prostheses.
CNA Tactics and Techniques: A Structure Proposal
Authors: Villalón-Huerta Antonio , Ripoll-Ripoll Ismael , Marco-Gisbert Hector
Published: February 2021

Destructive and control operations are today a major threat for cyber physical systems. These operations, known as Computer Network Attack (CNA), and usually linked to state-sponsored actors, are much less analyzed than Computer Network Exploitation activities (CNE), those related to intelligence gathering. While in CNE operations the main tactics and techniques are defined and well structured, in CNA there is a lack of such consensuated approaches. This situation hinders the modeling of threat actors, which prevents an accurate definition of control to identify and to neutralize malicious activities. In this paper, we propose the first global approach for CNA operations that can be used to map real-world activities. The proposal significantly reduces the amount of effort need to identify, analyze, and neutralize advanced threat actors targeting cyber physical systems. It follows a logical structure that can be easy to expand and adapt.
Function, Regulation, and Dysfunction of Intrinsically Disordered Proteins
Authors: Fusco Giuliana , Gianni Stefano
Published: February 2021

The discovery that a considerable fraction of the eukaryotic proteins lacks a well-defined three-dimensional structure in their native state has revolutionised our general understanding of proteins [...]
Radiation Tolerance and Charge Trapping Enhancement of ALD HfO2/Al2O3 Nanolaminated Dielectrics
Authors: Spassov Dencho , Paskaleva Albena , Guziewicz Elżbieta , Davidović Vojkan , Stanković Srboljub , Djorić-Veljković Snežana , Ivanov Tzvetan , Stanchev Todor , Stojadinović Ninoslav
Published: February 2021

High-k dielectric stacks are regarded as a promising information storage media in the Charge Trapping Non-Volatile Memories, which are the most viable alternative to the standard floating gate memory technology. The implementation of high-k materials in real devices requires (among the other investigations) estimation of their radiation hardness. Here we report the effect of gamma radiation (60Co source, doses of 10 and 10 kGy) on dielectric properties, memory windows, leakage currents and retention characteristics of nanolaminated HfO2/Al2O3 stacks obtained by atomic layer deposition and its relationship with post-deposition annealing in oxygen and nitrogen ambient. The results reveal that depending on the dose, either increase or reduction of all kinds of electrically active defects (i.e., initial oxide charge, fast and slow interface states) can be observed. Radiation generates oxide charges with a different sign in O2 and N2 annealed stacks. The results clearly demonstrate a substantial increase in memory windows of the as-grown and oxygen treated stacks resulting from enhancement of the electron trapping. The leakage currents and the retention times of O2 annealed stacks are not deteriorated by irradiation, hence these stacks have high radiation tolerance.
Antimicrobial Activity of Chitosan Oligosaccharides with Special Attention to Antiparasitic Potential
Authors: Silva Nayara Sousa da , Araújo Nathália Kelly , Daniele-Silva Alessandra , Oliveira Johny Wysllas de Freitas , Medeiros Júlia Maria de , Araújo Renata Mendonça , Ferreira Leandro De Santis , Rocha Hugo Alexandre Oliveira , Silva-Junior Arnóbio Antônio , Silva Marcelo Sousa , Fernandes-Pedrosa Matheus de Freitas
Published: February 2021

The global rise of infectious disease outbreaks and the progression of microbial resistance reinforce the importance of researching new biomolecules. Obtained from the hydrolysis of chitosan, chitooligosaccharides (COSs) have demonstrated several biological properties, including antimicrobial, and greater advantage over chitosan due to their higher solubility and lower viscosity. Despite the evidence of the biotechnological potential of COSs, their effects on trypanosomatids are still scarce. The objectives of this study were the enzymatic production, characterization, and in vitro evaluation of the cytotoxic, antibacterial, antifungal, and antiparasitic effects of COSs. NMR and mass spectrometry analyses indicated the presence of a mixture with 81% deacetylated COS and acetylated hexamers. COSs demonstrated no evidence of cytotoxicity upon 2 mg/mL. In addition, COSs showed interesting activity against bacteria and yeasts and a time-dependent parasitic inhibition. Scanning electron microscopy images indicated a parasite aggregation ability of COSs. Thus, the broad biological effect of COSs makes them a promising molecule for the biomedical industry.
Review of Transport Phenomena and Popular Modelling Approaches in Membrane Distillation
Authors: Dong Yan , Dai Xiaodong , Zhao Lianyu , Gao Li , Xie Zongli , Zhang Jianhua
Published: February 2021

In this paper, the transport phenomena in four common membrane distillation (MD) configurations and three popular modelling approaches are introduced. The mechanism of heat transfer on the feed side of all configurations are the same but are distinctive from each other from the membrane interface to the bulk permeate in each configuration. Based on the features of MD configurations, the mechanisms of mass and heat transfers for four configurations are reviewed together from the bulk feed to the membrane interface on the permeate but reviewed separately from the interface to the bulk permeate. Since the temperature polarisation coefficient cannot be used to quantify the driving force polarisation in Sweeping Gas MD and Vacuum MD, the rate of driving force polarisation is proposed in this paper. The three popular modelling approaches introduced are modelling by conventional methods, computational fluid dynamics (CFD) and response surface methodology (RSM), which are based on classic transport mechanism, computer science and mathematical statistics, respectively. The default assumptions, area for applications, advantages and disadvantages of those modelling approaches are summarised. Assessment and comparison were also conducted based on the review. Since there are only a couple of full-scale plants operating worldwide, the modelling of operational cost of MD was only briefly reviewed. Gaps and future studies were also proposed based on the current research trends, such as the emergence of new membranes, which possess the characteristics of selectivity, anti-wetting, multilayer and incorporation of inorganic particles.
Microtexture and Rolling Deformation Behavior Analysis of the Formation Mechanism Fe3O4 at the Interface Formed on Hot-Rolled High-Strength Steel
Authors: Wang Chao , Wu Huibin , Li Zhichao , Zhang Pengcheng , Li Leilei
Published: February 2021

In order to better understand the formation mechanism of tertiary oxide scale in high-strength steel during hot rolling, the microtexture of the oxide layer has been characterized and analyzed by the electron backscatter diffraction (EBSD) method. The results show that the Fe3O4 phase in the oxide layer has a two-phase heterogeneous morphology, Fe3O4 in the oxide layer comprises columnar grains, and Fe3O4 near the substrate comprises spherical grains. As the reduction rate increases, the Fe2O3 layer is gradually wedged into the surface of the Fe3O4 layer. Fe3O4 forms a <110> fiber texture at a reduction rate of 10%. The inner layer of the oxide scale comprises spherical grains, and Fe3O4 is preferentially nucleated and precipitated in the direction of Fe surface grains <110> texture. With the increase in the reduction rate, the {112}<−1−21> directional slip system shows the lowest Schmidt factor value, so the grains with a low Schmidt factor exhibit higher stored strain energy. The formation of the spherical Fe3O4 seam layer close to the steel matrix is the result of the combined effect of the stress state at the matrix and ion diffusion.
A Physical-Based Plane Stress Constitutive Model for High Strength AA7075 under Hot Forming Conditions
Authors: Chen Fulong , Qu Haitao , Wu Wei , Zheng Jing-Hua , Qu Shuguang , Han Yujie , Zheng Kailun
Published: February 2021

Physicallybased constitutive equations are increasingly used for finite element simulations of metal forming processes due to the robust capability of modelling of underlying microstructure evolutions. However, one of thelimitations of current models is the lack of practical validation using real microstructure data due to the difficulties in achieving statistically meaningful data at a sufficiently large microstructure scale. Particularly, dislocation density and grain size governing the hardening in sheet deformation are of vital importance and need to be precisely quantified. In this paper, a set of dislocation mechanics-based plane stress material model is constructed for hot forming aluminum alloy. This material model is applied to high strength 7075 aluminum alloy for the prediction of the flow behaviorsconditioned at 300–400 °C with various strain rates. Additionally, an electron backscatter diffraction (EBSD) technique was applied to examine the average grain size and geometrical necessary dislocation (GND) density evolutions, enabling both macro- and micro- characteristics to be successfully predicted. In addition, to simulate the experienced plane stress states in sheet metal forming, the calibrated model is further extended to a plane stress stateto accuratelypredict the forming limits under hot conditions.The comprehensively calibrated material model could be used for guidinga better selection of industrial processing parameters and designing process windows, taking into account both the formed shape as well as post formed microstructure and, hence, properties.
Presintered Titanium-Hydroxyapatite Composite Fabricated via PIM Route
Authors: Mahmud Nurul Nadiah , Sulong Abu Bakar , Sharma Bhupendra , Ameyama Kei
Published: February 2021

Ti6Al4V-HA composites have been recognized for their potential for biomedical implantation purposes. In the present study, Ti6Al4V-HA composites were fabricated by Powder Injection Molding (PIM) route. Ti6Al4V-HA feedstock at a ratio of 87:13 vol.% was prepared by using a binder system consisting of palm stearin (PS) and polyethylene (PE). The Critical Powder Volume Percentage (CPVP) value for Ti6Al4V-HA was 68 vol.%. Ti6Al4V-HA feedstock was developed at 66 vol.% powder loading. Ti6Al4V-HA feedstock showed pseudoplastic behaviour with a low viscosity and low activation energy of flow and was successfully injected into a tensile bar shape. The debinding process involved a solvent and thermal debinding operation. The debonded parts were sintered at 1300 °C, and the influence of the presintering stage on the physical and mechanical properties of the sintered parts was investigated. It was proven that the presintering stage was able to restrain the transformation of Ti6Al4V into Ti3Al (α2) as well as the decomposition of HA. These are key findings ideas for the designing of sintering parameters, where the decomposition of HA becoming the main problem in the sintering of Ti6Al4V-HA composites at a high temperature. The obtained results also showed that the sintered parts had a porous structure, which looked promising for their use in biomedical implantations. purposes.
A Metabolomics Analysis of Postmenopausal Breast Cancer Risk in the Cancer Prevention Study II
Authors: Moore Steven C. , Mazzilli Kaitlyn M. , Sampson Joshua N. , Matthews Charles E. , Carter Brian D. , Playdon Mary C. , Wang Ying , Stevens Victoria L.
Published: February 2021

Breast cancer is the most common cancer in women, but its incidence can only be partially explained through established risk factors. Our aim was to use metabolomics to identify novel risk factors for breast cancer and to validate recently reported metabolite-breast cancer findings. We measured levels of 1275 metabolites in prediagnostic serum in a nested case-control study of 782 postmenopausal breast cancer cases and 782 matched controls. Metabolomics analysis was performed by Metabolon Inc using ultra-performance liquid chromatography and a Q-Exactive high resolution/accurate mass spectrometer. Controls were matched by birth date, date of blood draw, and race/ethnicity. Odds ratios (ORs) and 95% confidence intervals (CIs) of breast cancer at the 90th versus 10th percentile (modeled on a continuous basis) of metabolite levels were estimated using conditional logistic regression, with adjustment for age. Twenty-four metabolites were significantly associated with breast cancer risk at a false discovery rate <0.20. For the nine metabolites positively associated with risk, the ORs ranged from 1.75 (95% CI: 1.29–2.36) to 1.45 (95% CI: 1.13–1.85), and for the 15 metabolites inversely associated with risk, ORs ranged from 0.59 (95% CI: 0.43–0.79) to 0.69 (95% CI: 0.55–0.87). These metabolites largely comprised carnitines, glycerolipids, and sex steroid metabolites. Associations for three sex steroid metabolites validated findings from recent studies and the remainder were novel. These findings contribute to growing data on metabolite-breast cancer associations by confirming prior findings and identifying novel leads for future validation efforts.
Characteristics of Black Ginseng (Panax ginseng C.A. Mayer) Production Using Ginseng Stored at Low Temperature after Harvest
Authors: Oh Hyo Bin , Lee Ji Won , Lee Da Eun , Na Soo Chang , Jeong Da Eun , Hwang Dae Il , Kim Young Soo , Park Chung Berm
Published: February 2021

Ginseng processing often involves multiple drying and heat treatments. Ginseng is typically processed within one week of harvesting or is stored at low temperatures to prevent spoilage. Black ginseng (BG) is manufactured by repeating the heat treatment and drying process of ginseng several times. We compared the suitability of low-temperature stored ginseng (SG) and harvested ginseng (HG) as the components for black ginseng production. SG and HG were processed into black ginseng and the appearance change, free sugar content, and benzo[a]pyrene (BAP) content were observed. Appearance observations showed the SG to be suitable in terms of quality when heat-treated at a temperature of 95 ℃ or higher. The BAP content of the SG increased significantly as the steaming process was repeated. A maximum BAP concentration of 5.31 ± 1.12 μg/kg was measured in SG steamed from 2 to 5 times, making it unsuitable for processing into BG. SG and HG showed similar trends in the content of sucrose, fructose, and glucose during steaming. This study aimed to facilitate the proper choice of base material to improve the safety of black ginseng by limiting BAP production during processing.
Effect of Interface Pretreatment of Al Alloy on Bonding Strength of the Laser Joined Al/CFRTP Butt Joint
Authors: Ye Yiyun , Zou Qi , Xiao Yinan , Jiao Junke , Du Beining , Liu Yuezhan , Sheng Liyuan
Published: February 2021

In the present research, the carbon fiber reinforced thermoplastic (CFRTP) was laser joined with the Al alloy whose joining interface was pretreated by laser micro-texturing, anodizing, and hybrid of laser micro-texturing and anodizing. The surface morphology of the pretreated Al joining interface and bonding strength of the corresponding Al/CFRTP butt joint were investigated. The results show that the laser micro-texturing has fabricated the micro-pit or micro-furrow in the Al joining interface. With the increasing of laser scanning times, the size of the micro-pit or micro-furrow decreases, when the laser scanning distance is constant. The bonding strength of the Al/CFRTP butt joint with Al joining interface pretreated by micro-texturing fluctuates with the increasing of laser scanning distance and times, reaching the maximum value of 20 MPa at laser scanning distance of 0.1 mm and 1 time. The anodizing pretreatment has formed the Al2O3 oxide layer on the Al joining interface. The Al/CFRTP butt joint with Al joining interface pretreated by anodizing obtains the maximum bonding strength of 11 MPa at anodizing time of 10 min. The hybrid pretreatment of micro-texturing and subsequent anodizing fabricates the regular grid structure with smooth micro-furrow and micro-pit, while the hybrid pretreatment of anodizing and subsequent micro-texturing fabricates the Al joining interface with explosive micro-pit and micro-furrow. The bonding strength of the Al/CFRTP butt joint with hybrid-pretreated Al joining interface is relative better than that of the Al/CFRTP butt joint with anodizing-pretreated Al joining interface but almost lower than that of the Al/CFRTP butt joint with micro-texturing pretreated Al joining interface. Such results should be attributed to the surface morphology of the Al joining interface.
Soft Finger Modelling and Co-Simulation Control towards Assistive Exoskeleton Hand Glove
Authors: El-Agroudy Mohammed N. , Awad Mohammed I. , Maged Shady A.
Published: February 2021

The soft pneumatic actuators of an assistive exoskeleton hand glove are here designed. The design of the actuators focuses on allowing the actuator to perform the required bending and to restrict elongation or twisting of the actuator. The actuator is then modeled using ABAQUS/CAE, a finite element modeling software, and the open loop response of the model is obtained. The parameters of the actuator are then optimized to reach the optimal parameters corresponding to the best performance. Design of experiment (DOE) techniques are then approached to study the robustness of the system. Software-in-the-loop (SiL) is then approached to control the model variables via a proportional-integral-derivative (PID) control generated by FORTRAN code. The link between the two programs is to be achieved by the user subroutine that is written, where the subroutine receives values from ABAQUS/CAE, performs calculations, and passes values back to the software. The controller’s parameters are tuned and then the closed loop response of the model is obtained by setting the desired bending angle and running the model. Furthermore, a concentrated force at the tip of the actuator is added to observe the actuator’s response to external disturbance.
Conformational Selection Mechanism Provides Structural Insights into the Optimization of APC-Asef Inhibitors
Authors: He Xinheng , Huang Ning , Qiu Yuran , Zhang Jian , Liu Yaqin , Yin Xiao-Lan , Lu Shaoyong
Published: February 2021

Metastasis is the major cause of death in colorectal cancer and it has been proven that inhibiting an interaction between adenomatous polyposis coli (APC) and Rho guanine nucleotide exchange factor 4 (Asef) efficaciously restrain metastasis. However, current inhibitors cannot achieve a satisfying effect in vivo and need to be optimized. In the present study, we applied molecular dynamics (MD) simulations and extensive analyses to apo and holo APC systems in order to reveal the inhibitor mechanism in detail and provide insights into optimization. MD simulations suggested that apo APC takes on a broad array of conformations and inhibitors stabilize conformation selectively. Representative structures in trajectories show specific APC-ligand interactions, explaining the different binding process. The stability and dynamic properties of systems elucidate the inherent factors of the conformation selection mechanism. Binding free energy analysis quantitatively confirms key interface residues and guide optimization. This study elucidates the conformation selection mechanism in APC-Asef inhibition and provides insights into peptide-based drug design.
A Simple Cerium Coating Strategy for Titanium Oxide Nanotubes’ Bioactivity Enhancement
Authors: De Santis Serena , Sotgiu Giovanni , Porcelli Francesco , Marsotto Martina , Iucci Giovanna , Orsini Monica
Published: February 2021

Despite the well-known favorable chemical and mechanical properties of titanium-based materials for orthopedic and dental applications, poor osseointegration of the implants, bacteria adhesion, and excessive inflammatory response from the host remain major problems to be solved. Here, the antioxidant and anti-inflammatory enzyme-like abilities of ceria (CeOx) were coupled to the advantageous features of titanium nanotubes (TiNTs). Cost-effective and fast methods, such as electrochemical anodization and drop casting, were used to build active surfaces with enhanced bioactivity. Surface composition, electrochemical response, and in vitro ability to induce hydroxyapatite (HA) precipitation were evaluated. The amount of cerium in the coating did not significantly affect wettability, yet a growing ability to induce early HA precipitation from simulated body fluid (SBF) was observed as the oxide content at the surface increased. The presence of 4%wt CeOx was also able to stimulate rapid HA maturation in a (poorly) crystalline form, indicating an interesting potential to induce rapid in vivo osseointegration process.
Enhancing the UV Emission in ZnO–CNT Hybrid Nanostructures via the Surface Plasmon Resonance of Ag Nanoparticles
Authors: Rauwel Protima , Galeckas Augustinas , Rauwel Erwan
Published: February 2021

The crystal quality and surface states are two major factors that determine optical properties of ZnO nanoparticles (NPs) synthesized through nonaqueous sol–gel routes, and both are strongly dependent on the growth conditions. In this work, we investigate the influence of the different growth temperatures (240 and 300 °C) on the morphology, structural and crystal properties of ZnO NP. The effects of conjoining ZnO NP with carbon nanotubes (CNT) and the role of surface states in such a hybrid nanostructure are studied by optical emission and absorption spectroscopy. We demonstrate that depending on the synthesis conditions, activation or passivation of certain surface states may occur. Next, silver nanoparticles are incorporated into ZnO–CNT nanostructures to explore the plasmon–exciton coupling effect. The observed enhanced excitonic and suppressed defect-related emissions along with blue-shifted optical band gap suggest an intricate interaction of Burstein–Moss, surface plasmon resonance and surface band-bending effects behind the optical phenomena in hybrid ZnO–CNT–Ag nanocomposites.