bluuebunny/crossref_metadata_2025 huggingface dataset:
The Orthodontic Mini-Implants Failures Based on Patient Outcomes: Systematic Review
Authors: Tarigan Siti Harlianti Putri , Sufarnap Erliera , Bahirrah Siti
Published: October 2023

Anchorage is a challenge and essential issue for an orthodontist in determining the success of orthodontic treatment. Orthodontic anchorage is defined as resistance to unwanted tooth movement. Mini-implant is one of the devices that can be used as an anchor in orthodontic treatment. Many cases have reported successful treatment using mini-implant, but there are cases where mini-implants may fail. Failure of mini-implants can affect orthodontic treatment, and it is known that several factors may lead to mini-implant loss in orthodontic treatment. This systematic review aimed to determine the factors influencing mini-implant failure in orthodontic treatment. Articles were selected from electronic databases (PubMed, Google Scholar, The Cochrane Library, ScienceDirect) from January 2015 until 2023 according to the PRISMA method (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) under the PEOS (Population-Exposure-Outcome-StudyType) framework questions for systematic review. The study was registered in the International Prospective Register of Systematic Reviews (PROSPERO) database (CRD42022337684). All data collected were in English, and filtering was done by eliminating duplicate data, meta-analysis, case reports, case series, mini-reviews, and animal studies. The analysis was further divided into three groups, that is, patient-related, implant-related, and operator-related and operator-related (A graphical abstract provided as a Supplementary information [available in the online version]). Twenty-one articles were identified according to the inclusion criteria in the form of retrospective, prospective, in vivo, and randomized controlled trial studies. Mini-implant failures due to patient-related showed six etiological factors, failures due to implant-related had eight etiological factors, and only one factor was operator-related, which may lead to mini-implant failure. The data was extracted without a computerized system and only in English. Mini-implant failure can be caused by many factors; we could not accuse one major factor as a cause. However, the quality or condition of the bones and oral hygiene are factors that play a significant role in obtaining the stability of implants. Mini-implant failure is highly influenced by poor oral hygiene and peri-implant inflammation. Comprehensive diagnostic prior to mini-implant insertion should be appropriately considered. This systematic review describes several factors that can influence mini-implant failure, divided into three groups: patient-related, implant-related, and operator-related (A graphical abstract provided as a Supplementary information [available in the online version]).
Allogenic Acellular Dermal Matrix and Xenogeneic Dermal Matrix as Connective Tissue Graft Substitutes for Long-Term Stability Gingival Recession Therapy: A Systematic Review and Meta-Analysis
Authors: Halim Felita Clarissa , Sulijaya Benso
Published: October 2023

Connective tissue graft (CTG) serves as a gold standard for gingival recession therapy. Yet the availability of CTG is limited, and it increases patient morbidity. Allogenic acellular dermal matrix (AADM) and xenogeneic dermal matrix (XDM) have been proven to be effective substitutes of CTG although the long-term stability is unclear. The aim of this study was to analyze the long-term stability outcome of gingival recession therapy using AADM and XDM compared to CTG. This study follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Data were extracted independently from several online databases (PubMed, Scopus, and Embase). Five of 233 publications were included for final qualitative analysis and meta-analysis focusing on the mean difference of clinical parameters such as recession depth (RD), recession width (RW), probing depth (PD), clinical attachment loss (CAL), tissue thickness (TT), keratinized tissue width (KTW), and mean root coverage (MRC). Meta-analyses of RD, RW, CAL, TT, KTW, and MRC display an overall mean of 0.2 mm (95% confidence interval [CI]: –0.45 to –0.05), 0.29 mm (95% CI: –0.65 to 0.08), 0.2 mm (95% CI: –0.69 to 0.29), 0.25 mm (95% CI: –0.53 to 0.03), 0.26 mm (95% CI: –0.5 to 0.02), and 9.19% (95% CI: –13.95 to –4.43]), respectively, favoring the CTG. PD was the only parameter that favored the AADM or XDM with an overall mean of 0.03 mm (95% CI: –0.05 to 0.11). In all, if the long-term stability is the goal, the CTG is considered superior for gingival recession therapy. However, if it is contraindicated, the AADM and XDM might be considered as alternatives.
Stress Analysis of Endodontically Treated Tooth–Implant Different Connectors Designs in Maxillary Posterior Region: A Finite Element Analysis
Authors: Hashemi Sara , Baghaei Kimia , Fathi Amirhossein , Aghadavoudi Navid , Hashemi Seyed Saman , Atash Ramin , Khademi Sayed Sobhan
Published: October 2023

Objectives Using finite element analysis (FEA), this study aimed to determine the effect of nonrigid connectors (NRCs) and their position on the success of tooth and implant-supported fixed prostheses in the maxillary posterior region.

Materials and Methods Three three-dimensional FEA models were designed, presuming maxillary second premolar and first molar to be extracted. Implant (replacing first molar), abutment, bone (spongious and cortical), first premolar (containing dentin, root cement, gutta-percha, and casting post and core), periodontal ligament, and three three-unit cemented porcelain-fused-to-metal prostheses (a rigid one and two nonrigid) were modeled. The NRC was once on the tooth side and once on the implant side. The prostheses were loaded twice. The first molar (180 N) and premolars (120 N) teeth were subjected to progressive vertical and oblique (12-degree) loads, and maximum von Mises stress and strain in teeth and connectors were calculated for each model.

Results The findings of the current study showed evidence that tooth-implant design with an NRC has significantly increased the average stress in the tooth. The average stress in dentin was 769.02 for the mesial connector and 766.95 for the distal connector, and this was only 731.59 for rigid connector. Furthermore, it was observed that rigid connector has considerably minimized the stress within the tooth–implant-supported fixed partial denture. The average stress for the crown and metal frame is 346.22 and 526.41 in rigid connector, while it is 1,172.9 and 2,050.9 for the nonrigid mesial connector.

Conclusion Although distal NRC was more efficient than mesial NRC, using NRC will only reduce the stress applied to cortical bone and is not recommended in the posterior region of the maxilla.
Comparing the Effectiveness of Conventional and Microsurgical Access Flap Techniques in Managing Horizontal Bony Defects in Chronic Periodontitis Patients: A Clinical and Radiographic Study
Authors: Thakur Shambhavi , Martande Santosh , Ankit Kumar , Gopalakrishnan D. , Kulloli Anita , Shetty Sharath , Mehta Vini , Suryawanshi Krishna
Published: October 2023

Objective Periodontal microsurgery is descendant of conventional periodontal surgery to reduce surgical trauma, improve wound healing, and enhance patient compliance. This study compared the efficacy of conventional and microsurgical access flap in the management of horizontal bony defects in chronic periodontitis patients.

Materials and Methods Eight pairs of contralateral horizontal bone defects in chronic periodontitis patients were randomly allocated to control group and test group. Microsurgical access flap was carried out in test group under magnification, while control group received conventional access flap. Plaque index (PI), gingival index (GI), probing pocket depth (PPD), relative attachment level (RAL), and relative gingival marginal level (RGML) were recorded at baseline, 3 months, and 6 months. Wound healing index (WHI) was evaluated after 1 week, 2 weeks, and 4 weeks. Pain perception was evaluated using visual analog scale (VAS) post-surgery and after 24 hours. Radiographic defect depth was measured at baseline and after 6 months.

Statistical Analysis The statistical analysis was done by SPSS statistical software. The intragroup comparison was done by repeated measures analysis of variance. The intergroup difference between both groups was done by Student's t-test. The descriptive statistics for VAS and WHI was done by Wilcoxon signed rank test. The mean difference between clinical parameters from baseline to follow-up intervals was calculated by post-hoc least significance difference analysis.

Results There was significant reduction in PI, GI, PPD, and RAL within both the groups (p < 0.05). There was increase in RGML within both the groups from baseline to 6 months (p < 0.05). In the intergroup comparison, test group showed better WHI and better pain perception (VAS) compared to control group (p < 0.05). No difference was found between both the groups in terms of radiographic defect depth (p > 0.5).

Conclusion Both the procedures were effective in improving the clinical parameters but the microsurgical group showed better results in terms of wound healing and less postoperative pain. Both procedures showed no significant effect on radiographic defect depth.
Homodigital Unipedicled Islanded Neurovascular Pulp Advancement Flap/Colombo Flap for Fingertip Reconstruction: A Case Series with a Novel Technique
Authors: Rankothkumbura Jeewan Pradeep , Prasad Iddagoda Hewage Don Samitha , Gayamali Gamini Kaushalya , Dissanayake Dammika Abeywickrama
Published: October 2023

Fingertip injury is the most common type of upper extremity injury. Operative treatment with flap cover is required for tissue loss causing bone exposure and when there is a compelling need to preserve the length, unless microvascular replantation is possible. There are many techniques described for this purpose offering varying degrees of good outcomes. Yet there are limitations and long-term problems. We report a case series with a novel technique named “Colombo flap,” which is a neurovascular islanded advancement flap based on a single pedicle. Five fingers of four consented patients were operated using this technique and they were followed up for 2.5 years. All had satisfactory sensory recovery (S3 +/S4), preserved range of motion (ROM) at interphalangeal joints, good grip strengths, and satisfactory outcomes based on Michigan Hand Questionnaire (MHQ). There were no complications such as flap necrosis, infection, and neuroma formation. Hook nail deformity was minimal and none had pain or cold intolerance.
Recipient Vessel Dissection Technique in Diabetic Foot Patients with Perivascular Fibrosis
Authors: Periasamy Madhu , Muthukumar Vamseedharan , Venkatramani Hari , Sabapathy S. Raja
Published: October 2023

Diabetic foot ulcers are becoming more prevalent, and microsurgical free flaps are gaining popularity in salvaging the foot after postdebridement. The perivascular fibrosis around the recipient vessels often makes the dissection of vessels difficult. In this article, we describe a technique of dissection in such situations where fibrosis and dissection of vessels are fraught with danger. In the period from November 2020 to May 2023, 72 free flap reconstructions of the diabetic foot were done at our institute using this technique, with a success rate of 95.8%.
Endoscopic Endonasal Approach to Orbital Malignant Peripheral Nerve Sheath Tumor: A Minimally Invasive Method for Rare Orbital Tumor—Case Report and Review of Literature
Authors: Ganigi Praveen M. , Chakraborty Arijit , Bopanna K.M. , Shetty Sathwik R.
Published: October 2023

Malignant peripheral nerve sheath tumors (MPNSTs) are uncommon tumors that rarely occur in the orbit. Malignant orbital tumors are always a challenge to remove completely. We present the case of a 42-year man with painful movement of the left eye and restriction of adduction of the left eye causing double vision. Magnetic resonance imaging (MRI) of the brain/orbit revealed intraconal tumor located inferomedial to the optic nerve. The imaging features were suggestive of schwannoma or cavernoma. Gross total resection of the tumor was done with an endoscopic endonasal intraconal approach. The histopathology revealed an MPNST. The patient received adjuvant radiotherapy and chemotherapy. His left eye adduction recovered completely and he had no local recurrence or systemic metastasis on follow-up evaluation.
Management of Post–Electric Burn Microstomia by Free Radial Artery Forearm Flap in a 1-Year-Old Child
Authors: Manas Raj Kumar , Chatterji Sujoy Kumar
Published: October 2023

Management of post–electric burn microstomia is a challenging task, especially in children, as it causes difficulty in feeding and airway problems (secondary to nasal airway blockage). The recreated defect is often full thickness and requires full-thickness tissue for reconstruction. The free flap can provide adequate normal tissue for the restoration of functions and aesthesis of the perioral region. However, performing free flaps in children is equally demanding due to small-diameter vessel anastomosis and postoperative monitoring. We present a case of postburn microstomia that was managed by contracture release and reconstruction by free radial artery forearm flap in a 1-year-old child. Postoperatively, at 6 months of follow-up, the flap settled well and the child was able to open his mouth fully with good aesthetic outcome. The free flap can be considered a good and safe option for perioral contracture release and reconstruction for better functional and aesthetic outcomes.
Restoring Quality of Life: Assessing the Impact of Free Flap Reconstruction in Coronavirus Disease 2019-Associated Rhino-Orbital Mucormycosis Patients
Authors: Rao Neeraj , Agrawal Anand , Kapoor Akshay , Mago Vishal , Vathulya Madhubari , Chattopadhyay Debarati
Published: October 2023

Background In India, between May 5 and July 2021, 41,512 cases and 3,554 deaths due to mucormycosis were reported in coronavirus disease 2019 (COVID-19)-infected patients or COVID-19-recovered patients. COVID-19-associated rhino-orbital mucormycosis (CAROM) has been associated with adverse effects that can affect oral health, vision, and physical as well as emotional functioning. After the radical debridement of CAROM and antifungal therapy, reconstructive surgery should be employed to restore function and aesthetics; however, limited clinical data exist on its potential effect on the quality of life (QOL) of these patients.

Objective Our objective was to assess the QOL among CAROM patients reconstructed with free flap surgery.

Materials and Methods This analysis studied 19 patients of CAROM who had maxillectomy and/or orbital exenteration defects reconstructed with free flaps at a tertiary care center. All these patients were free from any residual disease, as confirmed by tissue biopsy taken from the affected area. The QoL of these patients was assessed 1 week preoperatively and 4 to 6 months postoperatively using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Head and Neck Module (EORTC QLQ-HN43) questionnaire module.

Results There was a statistically significant improvement in 10 out of the total 19 parameters (p < 0.05) which include pain in the mouth, problems opening mouth, speech, swallowing, weight loss, dry mouth and sticky saliva, body image, fear of progression, social contact, and social eating.

Conclusion The EORTC QLQ-HN43 questionnaire module presented a statistically significant improvement in the functional as well as psychological status of the CAROM patients undergoing reconstruction by free flap surgery.
Failure of Reconstructive Technique to Repair a Giant Intracranial Fusiform Aneurysm of the Basilar Artery: Case Report and Literature Review in the Pediatric Population
Authors: Solis Frank G. , Toledo Mauro , Ecos Rosa L.
Published: October 2023

Treatment of giant basilar aneurysm presents a major treatment challenge, especially in the pediatric population. Morbidity and mortality approach 80 and 30%, respectively. Both reconstructive and deconstructive techniques are associated with high rates of complete occlusion and good neurological outcomes. We report a 14-year-old male with a giant basilar trunk aneurysm treated with an endovascular approach. Clinical symptoms began following an ischemic stroke 2 weeks prior to admission. Endovascular treatment was performed through a reconstructive technique by single flow diverter device (FDD) in the basilar artery; however, this technique failed. At 1-year follow-up, without additional endovascular treatment, the mid-basilar artery and aneurysm were occluded, with vertebrobasilar flow maintained through collaterals from the right posterior communicating artery. We present a challenging management of giant basilar aneurysm in a pediatric patient experiencing a failure of FDD deployment; however, we highlight the importance of collateral flow development in progressive occlusions.
Initial Experiences in Adolescents and Young Adults with T-Cell Acute Lymphoblastic Leukemia/Lymphoma Treated with the Modified BFM 2002 Protocol in a Resource-Constrained Setting
Authors: Jinwala Prutha , Patidar Rajesh , Bansal Shashank , Asati Vikas , Shrivastava S.P. , Elhence Aditya , Patel Swati , Chitalkar P.G.
Published: October 2023

T-cell acute lymphoblastic leukemia/lymphoblastic lymphoma (T-ALL/LBL) in adolescents and young adults (AYAs) is a clinically aggressive malignancy and life-threatening at diagnosis. Intensive chemotherapy protocols, inspired by the Berlin-Frankfurt-Münster (BFM) regimen, along with central nervous system (CNS) prophylaxis, have achieved a 75 to 85% 5-year disease-free survival rate. However, in cases of marrow and CNS relapses, second-line chemotherapy is usually ineffective. This study aimed to assess the safety and efficacy of the BFM 2002 protocol and to correlate clinical profiles and prognostic factors with survival outcomes in AYA T-ALL/LBL patients. We retrospectively analyzed data from T-ALL/LBL patients treated at the Department of Medical Oncology, Sri Aurobindo Institute of Medical Sciences (SAIMS), Indore, between 2018 and 2021. Twenty-one patients aged 15 to 29 years were studied for their clinical course and laboratory parameters over 36 months. Diagnosis and risk stratification were performed following the guidelines of the BFM 2002 protocol. All patients received treatment and monitoring according to this pediatric-inspired protocol. The median age of the patients was 17 years (range: 15–28 years). Eleven patients presented with mediastinal lymph node enlargement, 10% exhibited CNS involvement, and none had testicular involvement. Eleven patients had marrow blasts greater than 25%, indicative of acute lymphoblastic leukemia. All 21 patients were treated according to the intensive modified BFM 2002 protocol and achieved morphological remission after a median follow-up of 24 months (range: 18–36 months). Seventeen patients achieved minimal residual disease (MRD) negativity post-induction. MRD at day 33 showed a significant association with the probability of disease relapse (p = 0.0015). There were five deaths (24%), one due to toxicity and four due to relapse. The study recorded an 18-month overall survival of 76%. These results were achieved despite financial constraints. Data were entered into a spreadsheet, and statistical analysis was performed using IBM SPSS version 23. Continuous data are presented as ranges and medians, while categorical variables are shown as percentages and numbers. A chi-squared test for association, with a significance level set at p < 0.05, was conducted as indicated. AYA T-ALL/LBL requires intensive treatment regimens. With biological characterization of LBL/ALL and close therapy monitoring, encouraging outcomes can be achieved even in resource-limited settings.
A Prospective Randomized Controlled Trial to Study the Role of Sulfasalazine in the Prevention of Acute Gastrointestinal Toxicities in Patients of Carcinoma of the Cervix Receiving Concurrent Chemoradiation
Authors: Abhinav Vasireddy , Darisi Naga Chandra Sekhar , Iyyapu Amrutha , Konakalla V.L Anusha
Published: October 2023

The present study aimed to evaluate the effectiveness of sulfasalazine in preventing acute gastrointestinal (GI) toxicities in patients with cervical carcinoma receiving concurrent chemoradiation. This prospective randomized controlled study was conducted at the Department of Radiotherapy from November 2016 to April 2018. A total of 60 eligible patients (30 in arm A and 30 in arm B) were enrolled in the study. Patients in arm A received 5,000 cGy of external beam radiotherapy (EBRT) in 25 fractions concurrently with chemotherapy using cisplatin (40 mg/m2 weekly) and tablet sulfasalazine (1 g twice a day). Patients in arm B received 5,000 cGy of EBRT in 25 fractions concurrently with chemotherapy using cisplatin (40 mg/m2 weekly) without any prophylactic medication. The acute GI toxicities assessed in this study included diarrhea, abdominal pain, tenesmus, and rectal bleeding. The chi-squared test was employed to compare the toxicity grades in the two arms. The collected data were analyzed using Statistical Package for Social Sciences (SPSS) version 21, with statistical significance considered at p < 0.05. The results showed a significant decrease in the incidence of grade 2 or higher diarrhea in the study arm compared to the control arm. Additionally, there was a decrease in the incidence of grade 1 or higher abdominal pain in the study arm. A decrease in the incidence of grade 1 or higher tenesmus was also observed, although the difference was not statistically significant. Rectal bleeding decreased significantly. Sulfasalazine was found to be a cost-effective and safe method for reducing the incidence of radiation-induced acute GI toxicities in cervical carcinoma patients undergoing radiotherapy.
Study on the performance test of Fe–Ce–Al/MMT catalysts for phenol-containing wastewater
Authors: Su Xiaoping , Wang Xiangtong , Li Longjian , Li Ning , Liu Xuanchi , Zhang Ping
Published: October 2023

In this study, a series of Fe–Ce–Al/MMT catalysts were prepared, characterized by XRD, SEM and N2 adsorption/desorption, and treated with phenol-containing wastewater. The results showed that the optimal Fe–Ce–Al/MMT catalyst with a molar ratio of (Fe + Ce)/(Fe + Ce + Al) of 5.5% has better grain development, more regular appearance, more uniform particle distribution, specific surface area of 180.9 m2/g and pore volume of 0.1858 cm3/g. The optimum technological conditions obtained by single factor test are as follows: initial pH value was 4, dosage of H2O2 was 13 mL/L, dosage of Fe2+ was 3500 mg/L, reaction temperature was 60 °C, and reaction time was 180 min. Under these conditions, the phenol removal rate was 98.21%. Based on the single factor test, the response surface test was carried out, and the results are as follows: initial pH value was 3, dosage of H2O2 was 15.64 mL/L, dosage of Fe2+ was 4884.37 mg/L, reaction temperature was 53.05 °C, and reaction time was 217.1 min. Under these conditions, the phenol removal rate was up to 98.75%.
Importance of the fundamental entropy for determining interfacial thermal resistance temperature jump differences
Authors: Standnes Dag Chun , Kristoffersen Anders
Published: October 2023

This work presents a method for calculating the difference in temperature jumps observed at the solid–water and water–solid interfaces when heat is flowing under steady state conditions from a hot to a cold solid separated by an intermediate water phase. The method is based on a hypothesis stating that the entropy flux is maximized where the heat flux is constrained, i.e., at the solid–water interfaces. By focusing on the entropy rather than the heat flux and by maximizing its value vs the magnitude of the temperature jump over the interfaces where the latter is constrained, simple analytical expressions for the jump differences independent of the actual heat flux are established only depending on the absolute temperature of the hot and cold solid. The results show that the temperature jump at the hotter interface, therefore, must be higher than the jump at the colder because of the differences in absolute temperature between the two interfaces, supported by many observations. The results, furthermore, show that the temperature jump asymmetry between the two interfaces should increase with decreasing absolute temperature of the system. The work, therefore, finally indicates that there are two quantities contributing to the magnitude of any temperature jump, the heat and entropy flux. More investigations about their relationship under different conditions are encouraged since the topic is not systematically acknowledged and, therefore, investigated in the literature.
Comprehensive understanding on phosphorus precipitation in heavily phosphorus-doped Czochralski silicon
Authors: Wu Defan , Zhao Tong , Ye Bin , Chen Hao , Liang Xingbo , Li Shenzhong , Tian Daxi , Yang Deren , Ma Xiangyang
Published: October 2023

Heavily phosphorus-doped Czochralski (HP-CZ) silicon is an important substrate material for manufacturing power electronic devices. The high concentration of phosphorus impurities may be supersaturated during the crystal growth of HP-CZ silicon or device manufacturing. Thus, understanding phosphorus precipitation in HP-CZ silicon is of technological significance. Herein, a panoramic view of phosphorus precipitation in HP-CZ silicon is presented in terms of crystallography, thermodynamics, and kinetics. It is found that the orthorhombic SiP precipitates can form during the crystal growth of HP-CZ silicon and also during the post-anneals of HP-CZ silicon at 450–1050 °C. Along with increasing annealing temperature, the formed SiP precipitates tend to adopt the platelet, polyhedron, and sphere-like shapes. Moreover, the excess point defects, i.e., silicon self-interstitials and vacancies, are found to affect phosphorus precipitation occurring in the low and high temperature regimes in different ways. In light of the kinetics of phosphorus precipitation at different temperatures, it is deduced that phosphorus precipitation follows a growth law in compliant with Ham's theory to a large extent. As an important output of this work, the temperature-dependent phosphorus solubilities in the dislocation-free silicon, which have been hardly acquired previously, are derived on the basis of investigating phosphorus precipitation in a set of HP-CZ silicon wafers with different phosphorus concentrations. Moreover, the derived solvus line for the phosphorus impurities in silicon could be a beneficial supplement to the existing phase diagram of the Si–P binary system in the extremely silicon-rich corner.
Active terahertz frequency conversion on silicon-based time-varying metasurface
Authors: Jiang Yushun , Duan Siyu , Wu Jingbo , Qiu Hongsong , Zhang Caihong , Fan Kebin , Wang Huabing , Jin Biaobing , Chen Jian , Wu Peiheng
Published: October 2023

Terahertz (THz) metasurfaces have emerged as the preferred material for active devices, with numerous potential applications. However, due to a lack of materials with an ultrafast response, functional devices with fascinating time-varying phenomena remain to be explored. In this study, we experimentally investigated a time-varying THz metasurface with silicon–gold hybrid structures. The results show that the transmission spectra undergo a remarkable transformation when an optical pump is used. A transient time boundary is introduced to study the time-varying response using the sudden change in silicon conductivity in the presence of an optical pump. We observed the generation of new spectral components, and the magnitude of the converted wave is linear with the incident power. The proposed silicon-based THz time-varying metasurface paves the way for developing THz sources and nonlinear optical devices.
First-principles investigation of the effects of excess carriers on the polytype stability and stacking fault energies of SiC
Authors: Sakakima Hiroki , Izumi Satoshi
Published: October 2023

The characteristic polytype behaviors of SiC and accompanying low stacking fault energies are known to cause engineering issues, including polytype inclusions and bipolar degradation. The dependence of the relative stability of SiC polytypes and stacking fault energies on excess carrier concentration was investigated using first-principles calculations. The relative energy of 2H-, 4H-, and 6H-SiC to 3C-SiC increased with the excess electrons over 2 × 1019 cm−3, while the energy variation with excess holes was small. The stacking fault energies in 4H-SiC also exhibited a significant decrease with excess electrons over 1.0 × 1019 cm−3, whereas this change was minor with excess holes. These excess carrier dependencies were attributed to variations in the bandgap between polytypes. The energy level of the excess electrons was at the conduction band minimum; this was lowest in 3C-SiC, which had the lowest bandgap energy. Consequently, the energy of 3C-SiC with excess electrons was lower than that of other polytypes. Conversely, the valence band maximum lacked electrons when excess holes were present, resulting in a small difference among the Fermi levels of the polytypes. Hence, the energy difference between the SiC polytypes was similar for excess holes. Similarly, the stacking faults in SiC exhibited quantum-well structures by incorporating other polytypes with different bandgaps. With excess electrons, the Fermi level within the stacking faults was lower than that in the bulk crystals. Consequently, the stacking fault energy decreased for the same reason that the energy in 3C-SiC decreased under excess electron conditions.
Optical frequency divider: Capable of measuring optical frequency ratio in 22 digits
Authors: Shi H. , Jiang Y. , Yao Y. , Li B. , Wang C. , Yu H. , Ma L.
Published: October 2023

Recent advances in optical frequency standards and optical frequency combs (OFCs) have drawn wide attention since by transforming other quantities into frequency metrology, a higher measurement sensitivity or accuracy can be achieved. Among them, the search for dark matter, tests of relativity, and detection of gravitational wave anticipate even more precise frequency ratio measurement of optical signals, which challenges the state-of-the-art optical frequency standards and OFCs. Here, we report an optical frequency divider (OFD) based on a Ti:sapphire mode-locked laser, which can realize ultraprecise optical frequency ratio measurements and optical frequency division to other desired frequencies. The OFD is based on an OFC frequency-stabilized to a hydrogen maser, whose frequency noise in optical frequency division is subtracted via the transfer oscillator scheme. An optically referenced radio frequency time-base is introduced for the fine-tuning of the divisor and the reduction in division noise. Using the OFD, the frequency ratio between the fundamental and its second harmonic of a 1064 nm laser is measured with a fractional uncertainty of 3 × 10−22, nearly five times better than previous results. Meanwhile, we also report the ability to transport between laboratories, the long-term operation, and the multi-channel division of the OFD.
Patterns of direct contact condensation bubbles based on dynamic behaviors and oscillations
Authors: Yi Qihao , Ren Zibo , Zhao Ruiyong , Chen Hui , Zuo Zhigang , Liu Shuhong
Published: October 2023

The occurrence of periodic pressure oscillations caused by direct contact condensation (DCC) bubbles holds great significance in engineering. To investigate and control these oscillations associated with different bubble behaviors through experimental means, a steam flow with a mass flux ranging from 0.06–0.9 kg/h is introduced into a water bath at temperatures ranging from 40–85 °C through nozzles with diameters of 3, 4, and 5 mm. In this study, apart from the internal chugging (IC) behavior, both pressure oscillation and bubble behaviors are simultaneously studied and categorized into three distinct patterns: Bubble detachment type I (BD I), bubble detachment type II (BD II), and condensation oscillation. By considering bubble dynamics and employing dimensional analysis, we establish the dimensionless criteria RenPrJa for differentiating BD I from IC, as well as the critical Reynolds number Ren for distinguishing BD I from BD II. Subsequently, a dimensionless regime diagram is constructed to predict and evaluate the bubble behavior patterns with respect to oscillation under various test conditions. This regime diagram serves as a valuable tool for predicting and assessing the bubble behavior patterns associated with pressure oscillation in different operating scenarios.
Viscosity and Stokes-Einstein relation in deeply supercooled water under pressure
Authors: Mussa Alexandre , Berthelard Romain , Caupin Frédéric , Issenmann Bruno
Published: October 2023

We report measurements of the shear viscosity η in water up to 150 MPa and down to 229.5 K. This corresponds to more than 30 K supercooling below the melting line. The temperature dependence is non-Arrhenius at all pressures, but its functional form at 0.1 MPa is qualitatively different from that at all pressures above 20 MPa. The pressure dependence is non-monotonic, with a pressure-induced decrease of viscosity by more than 50% at low temperature. Combining our data with literature data on the self-diffusion coefficient Ds of water, we check the Stokes-Einstein relation which, based on hydrodynamics, predicts constancy of Dsη/T, where T is the temperature. The observed temperature and pressure dependence of Dsη/T is analogous to that obtained in simulations of a realistic water model. This analogy suggests that our data are compatible with the existence of a liquid-liquid critical point at positive pressure in water.
Plasmon-enhanced circular dichroism spectroscopy of chiral drug solutions
Authors: Venturi Matteo , Adhikary Raju , Sahoo Ambaresh , Ferrante Carino , Daidone Isabella , Di Stasio Francesco , Toma Andrea , Tani Francesco , Altug Hatice , Mecozzi Antonio , Aschi Massimiliano , Marini Andrea
Published: October 2023

We investigate the potential of surface plasmon polaritons at noble metal interfaces for surface-enhanced chiroptical sensing of dilute chiral drug solutions with nl volume. The high quality factor of surface plasmon resonances in both Otto and Kretschmann configurations enables the enhancement of circular dichroism differenatial absorption thanks to the large near-field intensity of such plasmonic excitations. Furthermore, the subwavelength confinement of surface plasmon polaritons is key to attain chiroptical sensitivity to small amounts of drug volumes placed around ≃100 nm by the metal surface. Our calculations focus on reparixin, a pharmaceutical molecule currently used in clinical studies for patients with community-acquired pneumonia, including COVID-19 and acute respiratory distress syndrome. Considering realistic dilute solutions of reparixin dissolved in water with concentration ≤5 mg/ml and nl volume, we find a circular-dichroism differential absorption enhancement factor of the order ≃20 and chirality-induced polarization distortion upon surface plasmon polariton excitation. Our results are relevant for the development of innovative chiroptical sensors capable of measuring the enantiomeric imbalance of chiral drug solutions with nl volume.
Life cycle integrated flow simulation for hydraulic fracturing horizontal wells in shale gas reservoirs
Authors: Sheng Guanglong , Deng Haiyang , Zhao Hui , Rui Zhenhua , Hu Ting , Liu Jinghua , Lu Mingjing
Published: October 2023

The distribution of matrix pressure and water saturation during the fracturing and shut-in period significantly impacts shale gas production. However, traditional numerical simulations primarily focus on the production period, often overlooking the impact of fracturing and shut-in on the seepage field and production rates. This study uses the dual-porosity/dual-permeability-embedded discrete fracture model (DPDK-EDFM) to characterize matrix mixed wettability and the natural/hydraulic fracture geometry. A multiscale numerical simulation model is constructed to encompass the whole life cycle of shale fracturing, shut-in, and production. The model provides a comprehensive understanding for considering the changes in rock properties and the diverse migration mechanisms. Subsequently, the life cycle model is used for sensitivity analysis on capillary pressure, shut-in time, and fracturing fluid volume. The findings demonstrate that (1) capillary pressure strongly impacts flowback rate. As surface tension increases from 0 to 72 mN/m, the flowback rate decreases from 113.00% to 68.25%. (2) The shut-in time strongly affects the uniformity of pressure distribution. (3) The fracturing fluid volume is directly proportional to the rise in formation pressure. This innovative model provides a robust framework for simulating and analyzing the seepage field behavior of shale gas reservoirs throughout the life cycle. Furthermore, through a comprehensive investigation of the main controlling factors, this study provides valuable insights into the efficient development of shale gas reservoirs, carrying both theoretical and practical significance.
Mode-resolved phonon transmittance using lattice dynamics: Robust algorithm and statistical characteristics
Authors: Yang Hong-Ao , Cao Bing-Yang
Published: October 2023

Lattice dynamics (LD) enables the calculation of mode-resolved transmittance of phonons passing through an interface, which is essential for understanding and controlling the thermal boundary conductance (TBC). However, the original LD method may yield unphysical transmittance over 100% due to the absence of the constraint of energy conservation. Here, we present a robust LD algorithm that utilizes linear algebra transformations and projection gradient descent iterations to ensure energy conservation. Our approach demonstrates consistency with the original LD method on the atomically smooth Si/Ge interface and exhibits robustness on rough Si/Ge interfaces. The evanescent modes and localized effects at the interface are revealed. In addition, bottom-up analysis of the phonon transmittance shows that the anisotropy in the azimuth angle can be ignored, while the dependency on the frequency and polar angle can be decoupled. The decoupled expression reproduces the TBC precisely. This work provides comprehensive insights into the mode-resolved phonon transmittance across interfaces and paves the way for further research into the mechanism of TBC and its relation to atomic structures.
Passivation of MXene via atomic layer deposition of SnO2 to achieve improved NO2 sensing
Authors: Zhou Lihao , Hu Yinhua , Li Shaobo , Liu Xianghong , Zhang Jun
Published: October 2023

MXene is a promising candidate for low power electronic devices, such as gas sensor at room temperature. However, achieving rapid response and complete recovery and simultaneously addressing the issue of baseline drift due to the oxidation of MXene are challenging for MXene sensors. Herein, we demonstrate a general strategy by using atomic layer deposition (ALD) to passivate Ti3C2Tx MXene. The abundant hydroxyl groups on MXene, which could lead to the oxidation of MXene, facilitate efficient deposition of SnO2. Gas sensor tests reveal that the passivated MXene@SnO2 exhibits a response of 35.2% to 20 ppm NO2, which is approximately three times higher than that of pure MXene. Importantly, the response time to NO2 was as fast as 18 s, with full and complete recovery to baseline within 27 s. Our strategy highlights the prospects of utilizing ALD technique for the development of MXene-based gas sensors.
Understanding conceptus–maternal interactions: what tools do we need to develop?
Authors: Butt Zenab , Tinning Haidee , O’Connell Mary J , Fenn Jonathan , Alberio Ramiro , Forde Niamh
Published: October 2023

Communication between the maternal endometrium and developing embryo/conceptus is critical to support successful pregnancy to term. Studying the peri-implantation period of pregnancy is critical as this is when most pregnancy loss occurs in cattle. Our current understanding of these interactions is limited, due to the lack of appropriate in vitro models to assess these interactions. The endometrium is a complex and heterogeneous tissue that is regulated in a transcriptional and translational manner throughout the oestrous cycle. While there are in vitro models to study endometrial function, they are static and 2D in nature or explant models and are limited in how well they recapitulate the in vivo endometrium. Recent developments in organoid systems, microfluidic approaches, extracellular matrix biology, and in silico approaches provide a new opportunity to develop in vitro systems that better model the in vivo scenario. This will allow us to investigate in a more high-throughput manner the fundamental molecular interactions that are required for successful pregnancy in cattle.
Sequence self-selection by cyclic phase separation
Authors: Bartolucci Giacomo , Calaça Serrão Adriana , Schwintek Philipp , Kühnlein Alexandra , Rana Yash , Janto Philipp , Hofer Dorothea , Mast Christof B. , Braun Dieter , Weber Christoph A.
Published: October 2023

The emergence of functional oligonucleotides on early Earth required a molecular selection mechanism to screen for specific sequences with prebiotic functions. Cyclic processes such as daily temperature oscillations were ubiquitous in this environment and could trigger oligonucleotide phase separation. Here, we propose sequence selection based on phase separation cycles realized through sedimentation in a system subjected to the feeding of oligonucleotides. Using theory and experiments with DNA, we show sequence-specific enrichment in the sedimented dense phase, in particular of short 22-mer DNA sequences. The underlying mechanism selects for complementarity, as it enriches sequences that tightly interact in the dense phase through base-pairing. Our mechanism also enables initially weakly biased pools to enhance their sequence bias or to replace the previously most abundant sequences as the cycles progress. Our findings provide an example of a selection mechanism that may have eased screening for auto-catalytic self-replicating oligonucleotides.
Rethinking replating
Authors: Short Ben
Published: October 2023

JGP study (In this issue, Osten et al. https://doi.org/10.1085/jgp.202313377) suggests that, by altering mechanosensitive signaling pathways, replating stem cell-derived cardiomyocytes changes myosin expression and contractile function.
Mathematical solutions in internal dose assessment: A comparison of Python-based differential equation solvers in biokinetic modeling
Authors: Mate-Kole Emmanuel Matey , Margot Dmitri , Dewji Shaheen Azim
Published: October 2023

In biokinetic modeling systems employed for radiation protection, biological retention and excretion have been modeled as a series of discretized compartments representing the organs and tissues of the human body. Fractional retention and excretion in these organ and tissue systems have been mathematically governed by a series of coupled first-order ordinary differential equations (ODEs). The coupled ODE systems comprising the biokinetic models are usually stiff due to the severe difference between rapid and slow transfers between compartments. In this study, the capabilities of solving a complex coupled system of ODEs for biokinetic modeling were evaluated by comparing different Python programming language solvers and solving methods with the motivation of establishing a framework that enables multi-level analysis. The stability of the solvers was analyzed to select the best performers for solving the biokinetic problems. A Python-based linear algebraic method was also explored to examine how the numerical methods deviated from an analytical or semi-analytical method. Results demonstrated that customized implicit methods resulted in an enhanced stable solution for the inhaled 60Co (Type M) and 131I (Type F) exposure scenarios for the inhalation pathway of the International Commission on Radiological Protection (ICRP) Publication 130 Human Respiratory Tract Model (HRTM). The customized implementation of the Python-based implicit solvers resulted in approximately consistent solutions with the Python-based matrix exponential method (expm). The differences generally observed between the implicit solvers and expm are attributable to numerical precision and the order of numerical approximation of the numerical solvers. This study provides the first analysis of a list of Python ODE solvers and methods by comparing their usage for solving biokinetic models using the ICRP Publication 130 HRTM and provides a framework for the selection of the most appropriate ODE solvers and methods in Python language to implement for modeling the distribution of internal radioactivity.
Interference-free laser-based temperature and CO-concentration measurements for shock-heated isooctane and isooctane/ethanol blends
Authors: He Dong , Si Ting , Fikri Mustapha , Luo Xisheng
Published: October 2023

Species concentration (e.g. CO) and temperature measurements in the combustion field require fast-response technique without interfering species. In the last decade, tunable diode lasers have been established as strong technique to measure species such as CO, CO2, and H2O as well as temperature with high sensitivity. The drawback is the degree of interference that might hamper the robustness of the technique. In this work simultaneous measurements of temperature and CO concentration were carried out using an interference-free mid-infrared laser-based absorption technique behind reflected shock waves. Two transition lines of CO (P(v″ = 0, J″ = 21) and P(v″ = 1, J″ = 21)) in the fundamental vibrational band near 4.87 and 4.93 μm, respectively, were selected. Absorbance interferences from CO2 and H2O at room and high temperatures were evaluated. Spectroscopic parameters for the development of the system were measured: line strengths and collisional broadening coefficients (in Ar) of both lines were obtained at 1020–1950 K by using the scanned-wavelength direct-absorption method. The technique was demonstrated for non-reactive and reactive mixtures. For the non-reactive case, temperature and CO concentration were measured at 1030–1910 K and 1.0–3.7 bar. For the reactive case, oxidation of i-C8H18/O2/Ar and i-C8H18/C2H5OH/O2/Ar mixtures were investigated at three equivalence ratios of 2.0, 1.0, and 0.5. The two newly adopted lines exhibited good performance in the detection of CO concentration and are immune to interferences from CO2 and H2O. In addition, the simulated data from the state-of-the-art isooctane/ethanol mechanisms in literature were compared with the measured data, showing overall good agreement.
Multi-valued perturbations on stochastic evolution equations driven by fractional Brownian motions
Authors: Ma Zhong-Xin , Valero José , Zhao Jia-Cheng
Published: October 2023

We consider a stochastic evolution inclusion having deterministic multi-valued nonlinearity and fractional Brownian motion with nonlinear diffusion. We establish the nonemptiness and compactness of its solution set. After that, the upper semicontinuity with respect to random parameters and initial values of the corresponding solution map is proved. In particular, the results on nonemptiness and upper semicontinuity imply that the inclusion under consideration defines a multi-valued random dynamical system. Moreover, under an extra smooth assumption on the diffusion, it is demonstrated that the solution set has the topological structure of R

δ
-type.