bluuebunny/crossref_metadata_2025 huggingface dataset:
Open flap debridement compared to repeated applications of photodynamic therapy in the treatment of residual pockets: A randomized clinical trial
Authors: Andere Naira M. R. B. , Castro dos Santos Nídia C. , Araújo Cássia F. , Paz Hélvis E. S. , Shaddox Luciana M. , Casarin Renato C. V. , Santamaria Mauro P.
Published: May 2022

Background

The aim of the present study was to compare repeated applications of antimicrobial photodynamic therapy (aPDT) to open flap debridement (OFD) in the treatment of residual periodontal pockets in non‐furcation sites.

Methods

Forty‐six subjects with a diagnosis of Stage III or IV Grade C periodontitis, that had been previously treated, participated in the study.  Residual pockets were divided between two groups: (1) aPDT group: received ultrasonic periodontal debridement followed by immediate application of aPDT, and repeated on1st, 2nd, 7th, and 14th days; and (2) OFD group: treated by modified papilla preservation technique, where granulation tissue and visible calculus were removed with hand curettes and an ultrasonic device. Clinical, immunological, and microbiological parameters were evaluated before and after treatment.

Results

Both treatments were effective reducing clinical parameters of disease. OFD resulted in a greater mean probing pocket depths (PPD) reduction in deep pockets (p = 0.001). However, aPDT resulted in a lower occurrence of gingival recession (GR), dentin hypersensitivity (DH) and analgesic intake. Reduction in Porphyromonas gingivalis was observed in both groups. Only the OFD group had a significant reduction in Aggregatibacter actinomycetemcomitans. aPDT group had greater increase in interleukin 10 (IL‐10) levels and a greater reduction of interleukin 1 beta (IL‐1β) at 14 days when compared to the OFD group (p < 0.05).

Conclusion

OFD was superior in reducing PPD in deep pockets compared to the aPDT. However, OFD resulted in greater GR.  Both treatments lowered P. gingivalis levels but only OFD reduced levels of A. actinomycemtemcomitans.
Intraoperative pectoral block versus thoracic paravertebral block for postoperative analgesia after breast cancer surgery: A randomized controlled trial
Authors: Sagun Aslinur , Rumeli Sebnem , Ozdemir Levent , Azizoglu Mustafa , Berkesoglu Mustafa , Mutlu Veli
Published: May 2022

Background and Methods

With the increasing rate of breast cancer surgery, the pain management of these patients gains importance. The aim of this study is to compare the ultrasound (US) guided thoracic paravertebral block (TPV) versus intraoperative pectoral nerve block (PECS) with a low volume local anaesthetic for postoperative analgesia after breast cancer surgery. A total of 41 patients underwent mastectomy and sentinel lymph node biopsy or modified radical mastectomy were included in this randomized controlled, single‐blinded trial. The patients were divided into two groups as PECS and TPV blocks. In the PECS group, 10 ml of 0.5% bupivacaine was administered to the fascial plane by the surgeon. In the TPV group, 25 ml of 0.25% bupivacaine at T3 level was administered by the anaesthetist under US‐guidance. Visual analogue scale (VAS) scores and additional analgesic requirements were recorded at postoperative 0, 6, 12, 24 and 48 h.

Results

In the TPV group, mean VAS score (VAS0) was significantly lower (p ˂ 0.001). In other time periods, there was no significant difference between the groups.

Conclusions

It was observed that intraoperative PECS block was as effective as TPV in providing postoperative analgesia and additional analgesic requirements were similar. This result suggests PECS block may be a good alternative to TPV.
Top Advances in Dermatologic Ultrasound
Authors: Wortsman Ximena
Published: May 2022

The advances in dermatologic ultrasound have been significantly influenced by the development of high‐ and ultrahigh‐frequency probes, the provision of guidelines for performing the examinations, and a growing number of publications in the field. This review analyzes the most significant contributions that have impacted the daily practice of dermatologists in recent years. This includes the advances in anatomical detection and the patterns of benign and malignant cutaneous tumors, inflammatory dermatologic conditions, vascular anomalies, nail abnormalities, and aesthetic procedures. The knowledge of these advances is a primer for the operators of these examinations.
A metric learning‐based method using graph neural network for pancreatic cystic neoplasm classification from CTs
Authors: Zhang Jiachen , Mao Yishen , Li Ji , Li Yiru , Luo Jianxu
Published: May 2022

Purpose

Pancreatic cystic neoplasms (PCNs) are relatively rare neoplasms and difficult to be classified preoperatively. Ordinary deep learning methods have great potential to provide support for doctors in PCNs classification but require a quantity of labeled samples and exact segmentation of neoplasm. The proposed metric learning‐based method using graph neural network (GNN) aims to overcome the limitations brought by small and imbalanced dataset and get fast and accurate PCNs classification result from computed tomography (CT) images.

Methods

The proposed framework applies GNN. GNNs perform well in fusing information and modeling relational data and get better results on dataset with small size. Based on metric learning strategy, model learns distance from the data. The similarity‐based algorithm enhances the classification performance, and more characteristic information is found. We use a convolutional neural network (CNN) to extract features from given images. Then GNN is used to find the similarity between each two feature vectors and complete the classification. Several subtasks consisting of randomly selected images are established to improve generalization of the model. The experiments are carried out on the dataset provided by Huashan Hospital. The dataset is labeled by postoperative pathological analysis and contains region of interest (ROI) information calibrated by experts. We set two tasks based on the dataset: benign or malignant diagnosis of PCNs and classification of specific types.

Results

Our model shows good performance on the two tasks with accuracies of 88.926% and 74.497%. The comparison of different methods' F1 scores in the benign or malignant diagnosis shows that the proposed GNN‐based method effectively reduces the negative impact brought by imbalanced dataset, which is also verified by the macroaverage comparison in the four‐class classification task.

Conclusions

Compared with existing models, the proposed GNN‐based model shows better performance in terms of imbalanced dataset with small size while reducing labeling cost. The result provides a possibility for its application into the computer‐aided diagnosis of PCNs.
Finite strip method based on Carrera unified formulation for the free vibration analysis of variable stiffness composite laminates
Authors: Daraei Behnam , Shojaee Saeed , Hamzehei‐Javaran Saleh
Published: May 2022

This work presents a refinement of the finite strip method (FSM) based on the Carrera unified formulation (CUF) and is applied to free vibration analysis of variable stiffness composite laminated (VSCL) plates. VSCL plates considered here are composed of layers with curvilinear fibers in which their orientation angle changes linearly with respect to one of the in‐plane coordinates. The FSM permits the plate to be divided into some finite strips connected along the so‐called nodal lines. The conventional finite strip method involves an approximation of the solution of a plate problem by using continuously harmonic series in the longitudinal direction along the nodal lines and simple polynomial shape functions (the usual beam shape functions) in the transverse direction of the plate. However, refined finite strip model that presented in this paper allows one to express the unknown variables as a set of thickness functions that only depend on the thickness coordinate and the corresponding variable that depends on the in‐plane coordinates which involve continuously harmonic series and polynomial shape functions. Thanks to this new finite strip model, the shape functions used in the transverse direction can be chosen as 1D bar shape functions, and also, all three components of the displacement field are considered in each nodal line. Moreover, based on this approach, three‐dimensional displacement field is approximated in a compact form as a generic N‐order expansion. Therefore, explicit expressions of fundamental nuclei of finite strip matrices are obtained in a compact form and presented here. The results obtained by the present formulation for VSCL plates are compared with those obtained from published data. The results show that this kind of strip is efficient and useful. Further, several numerical examples are presented, and the effect of the order of expansion, the number of strips, curvilinear fiber angle, and various boundary conditions are examined.
Analysis of an open foam generated from computerized tomography scans of physical foam samples
Authors: Leblanc Christophe , Kilingar Nanda Gopala , Jung Anne , Kamel Karim Ehab Moustafa , Massart Thierry Jacques , Noels Ludovic , Béchet Eric
Published: May 2022

The present article introduces an automated procedure to construct geometrical representative volume elements (RVE) of open‐foam cellular materials from computerized tomography (CT) images, with the final aim of generating meshable geometries usable in the finite element method (FEM) used in order to analyse their mechanical behavior. The methodology consists in growing and fitting a set of ellipsoids to each of the foam cells. These ellipsoids are seeded by local maxima of the distance to the struts obtained from computer tomography images. This methodology is thus fully voxel‐based and does not depend on any assumption about statistical distributions of the foam cells. Therefore, it is able to reproduce an accurate geometrical model of the foam's microstructure and its possible irregularities. Moreover, this procedure allows the processing of large 3D data sets that do not fit the random access memory (RAM) by slicing it into smaller independent chunks. The effectiveness of the proposed approach is illustrated by comparing it to FEM simulations for which meshes are obtained from a feature reconstruction approach. Both FEM simulations are then compared with experimental results of uniaxial compressions of an open foam.
Vibration analysis of piezoelectric Kirchhoff–Love shells based on Catmull–Clark subdivision surfaces
Authors: Liu Zhaowei , McBride Andrew , Saxena Prashant , Heltai Luca , Qu Yilin , Steinmann Paul
Published: May 2022

An isogeometric Galerkin approach for analysing the free vibrations of piezoelectric shells is presented. The shell kinematics is specialized to infinitesimal deformations and follow the Kirchhoff–Love hypothesis. Both the geometry and physical fields are discretized using Catmull–Clark subdivision bases. This provides the required ‐continuous discretization for the Kirchhoff–Love theory. The crystalline structure of piezoelectric materials is described using an anisotropic constitutive relation. Hamilton's variational principle is applied to the dynamic analysis to derive the weak form of the governing equations. The coupled eigenvalue problem is formulated by considering the problem of harmonic vibration in the absence of external load. The formulation for the purely elastic case is verified using a spherical thin shell benchmark. Thereafter, the piezoelectric shell formulation is verified using a one dimensional piezoelectric beam. The piezoelectric effect and vibration modes of a transverse isotropic curved plate are analyzed and evaluated for the Scordelis–Lo roof problem. Finally, the eigenvalue analysis of a CAD model of a piezoelectric speaker shell structure showcases the ability of the proposed method to handle complex geometries.
Trajectory tracking control based on memory data for robots with imprecise dynamic properties and interference
Authors: Wang Zhuo , Fang Mengliang
Published: May 2022

In this article, a new controller design method is proposed for the trajectory tracking problem of robots with imprecise dynamic properties and interference. By using the tracking error memory data of state variables to construct control law, the tracking errors caused by the system interference and inaccurate system modeling can be eliminated, and interference compensation can be realized, so that the system has the desired dynamic performance. The proposed method comes from the tracking control design of an affine nonlinear system. The controller is based on the error function of the control input in the ideal state and the actual state. According to the Lyapunov stability principle, it is proved that the proposed controller has good robustness under the conditions of bounded interference and inaccurate modeling. MATLAB was used to establish the controller and dynamic equation of the two‐joint planar robot for trajectory tracking simulation. Simulation results are presented to illustrate the performance of the proposed controller.
Mechanical and thermal analysis of coir fiber reinforced jute/bamboo hybrid epoxy composites
Authors: Sathish Thanikodi , Jagadeesh Praveenkumara , Rangappa Sanjay Mavinkere , Siengchin Suchart
Published: May 2022

In this current research study, nine different combinations of coir, jute, and bamboo reinforced epoxy composites were fabricated using casting technique. These composites were employed to mechanical tests such as flexural and impact tests, and analyzed the thermal stability through Thermogravimetric analysis (TGA) and Differential Scanning Calorimetry (DSC). Moreover, the thermal conductivity and surface morphology was also studied for hybrid composites. The hybridization of more than one fiber with epoxy matrix resulted in better mechanical and thermal properties as compared to individual reinforcements, and this statement is agreed with the present research work as well as the research works reported in the literature. The hybrid composite with the maximum amount of jute fibers reinforcement with bamboo fiber (B2C0J8) exhibited maximum flexural and impact strengths of 92.521 MPa and 82.4 kJ/m2respectively, which is due to the higher modulus and energy‐absorbing behavior of jute fibers, also it was an advantage of coir fibers absence having lower modulus and strength values. In thermal conductivity analysis, the marginal variations of values were observed with different volume fractions of fibers, and the maximum conductivity (0.317 W/m‐K) was obtained for B2C8J Composite having only coir and bamboo fiber reinforcements with epoxy matrix. The Thermogravimetric analysis results reveal that all nine types of hybrid composites possess nearly equal thermal stability, and slight variations in degradation temperatures were observed in the thermographs. The B2C1J7 hybrid composite was recommended for better mechanical and thermal properties, where it has 89.06 MPa of flexural strength, 78.6 kJ/m2of impact strength, 0.233 W/m‐K of thermal conductivity and exhibited better surface morphology.
Improvement of mechanical and antibacterial properties of silica‐filled styrene butadiene rubber composite by using cinnamaldehyde
Authors: Kandil Heba , Nour Shaimaa A.
Published: May 2022

In this study, cinnamaldehyde (CAD) was used as a filler modifier and antimicrobial material for silica‐filled styrene butadiene rubber (SBR) composite. CAD was used in different amounts to modify the silica surface. Fourier‐transform infrared spectroscopy (FTIR) was used to characterize the obtained CAD modified silicas. The modified silicas were mixed with SBR matrices using a laboratory two‐roll mill to produce modified silica‐filled SBR composites. The curing, mechanical, swelling and antibacterial properties of the resulting composites were studied and compared with those of the unmodified silica‐filled SBR composite. The surface morphologies of the obtained composites were also studied. The mechanical results showed that the use of 3 g of CAD resulted in a significant improvement in the mechanical properties of the resulting composite as its tensile strength, elongation at break and modulus at 100% increased by 144.9%, 105.1%, and 37.5%; respectively; compared to the unmodified composite. Furthermore, the antibacterial results showed that all the modified composites had a high activity against Gram+ and Gram− bacteria compared to the unmodified one, and this activity increased by increasing the amount of CAD. Accordingly, it is expected that these prepared composites can be used for medicinal purposes in the future.
Whole‐field strain distribution and fracture characteristics of CFRP‐repaired titanium plates with central inclined cracks
Authors: Chen Yiwei , Li Maojun , Su Ting , Yang Xujing
Published: May 2022

CFRP composites with the advantages of enhanced mechanical properties and lightweight are recognized as an ideal material in repairing cracked structures. This paper aims to comprehensively investigate whole‐field strain distribution and fracture characteristics of central inclined titanium plates repaired with CFRP laminates, with consideration of various overlap length and repair type. Results indicated that the initial central cracks significantly deteriorated mechanical performance, while inclined direction of it exhibited limited influence on repair behavior. Repairs with increased overlap length possessed superior mechanical performance and repair effectiveness. When increasing the overlap length to 80 mm, strength recovery rate for four types of repairs reached above 80.0%. Digital image correlation (DIC) results indicated that central hole was the highly strained zone for all repairs, and hole repairs presented relatively higher strain values compared with cracked repairs. Progressive failure analysis showed that repairs with initial cracks presented premature fracture of titanium plates, while hole repairs were capable to sustain load until adhesive layer fractured. Adhesive failure, cohesive failure and substrate fracture predominated on fractured surfaces irrespective of repair type and overlap length. With the increase of overlap length, cohesive failure was enhanced and light‐fiber‐tear/fiber‐tear could be found, which corresponded to relatively higher repair effectiveness.
A novel sound absorber foam based on ethylene propylene diene monomer (EPDM) to absorb low‐frequency waves: Influence of EPDM ethylene content
Authors: Hosseinpour Ali , Katbab Ali Asghar , Ohadi Abdolreza
Published: May 2022

In this study, a partially reticulated foam was fabricated based on ethylene propylene diene monomer rubber to absorb low‐frequency acoustic waves. The effect of ethylene content was studied on the cellular structure, viscoelastic behavior, and sound abortion characteristics. High airflow resistivity of the developed partially reticulated structure, as well as highly deformable cell walls of EPDM foams, led to large dissipation of sound energy at low and medium frequencies. Samples with lower ethylene content which exhibited lower storage modulus and larger pore sizes showed higher viscose motions with superior sound absorption. The foam sample with the lowest ethylene content offered the best sound absorption coefficient with a sharp peak as high as 0.91 within the 500–2500 Hz frequency range. The results imply the role of ethylene content as a molecular structure tool to optimize the acoustic absorption potential of EPDM foam. Besides, the foam samples showed considerable insulation performance, yielding a sound reduction index equal to 26–29 dB. The absorption and reflection of the sound waves were integrated to provide the insulation. Thus, a developed lightweight insulator with high resistance to harsh environmental conditions and great low‐frequency sound absorption could be achieved by structural engineering.
A Bayesian latent class model for predicting gestational age in health administrative data
Authors: Wang Shuang , Puggioni Gavino , Wen Xuerong
Published: May 2022

Health administrative data are oftentimes of limited use in epidemiological study on drug safety in pregnancy, due to lacking information on gestational age at birth (GAB). Although several studies have proposed algorithms to estimate GAB using claims database, failing to incorporate the unique distributional shape of GAB, can introduce bias in estimates and subsequent modeling. Hence, we develop a Bayesian latent class model to predict GAB. The model employs a mixture of Gaussian distributions with linear covariates within each class. This approach allows modeling heterogeneity in the population by identifying latent subgroups and estimating class‐specific regression coefficients. We fit this model in a Bayesian framework conducting posterior computation with Markov Chain Monte Carlo methods. The method is illustrated with a dataset of 10,043 Rhode Island Medicaid mother–child pairs. We found that the three‐class and six‐class mixture specifications maximized prediction accuracy. Based on our results, Medicaid women were partitioned into three classes, featured by extreme preterm or preterm birth, preterm or” early” term birth, and” late” term birth. Obstetrical complications appeared to pose a significant influence on class‐membership. Altogether, compared to traditional linear models our approach shows an advantage in predictive accuracy, because of superior flexibility in modeling a skewed response and population heterogeneity.
Anti‐inflammatory activities of natural cyclopeptide RA‐XII in colitis‐associated colon cancer mouse model and its effect on gut microbiome
Authors: Lin Qianwen , Liu Mingyu , Yue Grace Gar‐Lee , Cheung Man Kit , Lai Zhixing , Kwok Frankie Hin‐Fai , Lee Julia Kin‐Ming , Wang Zhe , Lau Clara Bik‐San , Tan Ninghua
Published: May 2022

Colorectal cancer (CRC), the third most common cancer globally, is associated with intestinal inflammation that leads to poor prognosis. RA‐XII, a natural cyclopeptide, has previously been reported to possess anti‐tumor activities. Here, the anti‐inflammatory activities of RA‐XII were investigated in colitis‐associated colon cancer mice and a co‐culture in vitro model, in which colon cancer cells HCT116 and macrophages RAW264.7 were grown together to mimic the inflammatory microenvironment of CRC. Changes of inflammatory‐related molecules and protein expressions in cells were evaluated after RA‐XII incubation. Besides, azoxymethane and dextran sulfate sodium‐induced colitis‐associated colon cancer mice were treated with RA‐XII for 24 days, inflammatory parameters and gut microbiome alterations were studied. Our results showed that RA‐XII reversed the inflammatory responses of RAW264.7 cells induced by LPS and modulated the protein expressions of AKT, STAT3/p‐STAT3, P70S6K, NF‐κB and GSK3β and suppressed the expression of LC3A/B in HCT116 cells in co‐culture system. RA‐XII treatment restored the colitis damage in colon, reduced colon tumors numbers and decreased inflammatory factors (IL‐6, IL‐10 and TNF‐α). The role of RA‐XII on regulating gut microbiome was also demonstrated for the first time. In conclusion, our findings provided new scientific evidence for developing RA‐XII as a potent anti‐inflammatory agent for CRC.
Regio‐ and Stereoselective Synthesis of Tetrasubstituted Alkenes via Ruthenium(II)‐Catalyzed C–H Alkenylation/Directing Group Migration
Authors: Mao Hui , Chen Jing , Zhang Xiaoning , Yu Na , Lu Yangbin , Zhao Fei
Published: May 2022

Herein we report the regio‐ and stereoselective synthesis of tetrasubstituted alkenes from N‐carbamoyl indoles and alkynes via ruthenium(II)‐catalyzed C−H alkenylation/directing group migration, in which the carbamoyl directing group is endowed with a dual role of auxiliary group and migrating acylation reagent via C−N bond cleavage. This method features broad substrate scope, high atom‐ and step‐economy, good functional group tolerance and mild redox‐neutral conditions at room temperature. A series of structurally diverse tetrasubstituted alkenes were synthesized in good to excellent yields, highlighting the efficiency of this method.
Precisely Localized Bone Regeneration Mediated by Marine‐Derived Microdroplets with Superior BMP‐2 Binding Affinity
Authors: Jeon Eun Young , Um Seung‐Hoon , Park Jaeho , Jung Youngmee , Cheon Cheol‐Hong , Jeon Hojeong , Chung Justin J.
Published: May 2022

Prompt and robust bone regeneration has been clinically achieved using supraphysiological doses of bone morphogenetic protein‐2 (BMP‐2) to overcome the short half‐life and rapid clearance. However, uncontrolled burst release of exogenous BMP‐2 causes severe complications such as heterotopic ossification and soft tissue inflammation. Therefore, numerous researches have focused on developing a new BMP‐2 delivery system for a sustained release profile by immobilizing BMP‐2 in various polymeric vehicles. Herein, to avoid denaturation of BMP‐2 and enhance therapeutic action via localized delivery, a complex coacervate consisting of fucoidan, a marine‐derived glycosaminoglycan, and poly‐l‐lysine (PLL) is fabricated. Superior BMP‐2 binding ability and electrostatic interaction‐driven engulfment enable facile and highly efficient microencapsulation of BMP‐2. The microencapsulation ability of the coacervate significantly improves BMP‐2 bioactivity and provides protection against antagonist and proteolysis, while allowing prolonged release. Moreover, BMP‐2 containing coacervate is coated on conventional collagen sponges. The bioactivity and localized bone regenerating ability are confirmed through in vitro (human‐derived stem cells), and in vivo (calvarial bone defect model) evaluations.
Bio‐Inspired In‐Sensor Compression and Computing Based on Phototransistors
Authors: Wang Rui , Wang Saisai , Liang Kun , Xin Yuhan , Li Fanfan , Cao Yaxiong , Lv Jiaxin , Liang Qi , Peng Yaqian , Zhu Bowen , Ma Xiaohua , Wang Hong , Hao Yue
Published: May 2022

The biological nervous system possesses a powerful information processing capability, and only needs a partial signal stimulation to perceive the entire signal. Likewise, the hardware implementation of an information processing system with similar capabilities is of great significance, for reducing the dimensions of data from sensors and improving the processing efficiency. Here, it is reported that indium‐gallium‐zinc‐oxide thin film phototransistors exhibit the optoelectronic switching and light‐tunable synaptic characteristics for in‐sensor compression and computing. Phototransistor arrays can compress the signal while sensing, to realize in‐sensor compression. Additionally, a reservoir computing network can also be implemented via phototransistors for in‐sensor computing. By integrating these two systems, a neuromorphic system for high‐efficiency in‐sensor compression and computing is demonstrated. The results reveal that even for cases where the signal is compressed by 50%, the recognition accuracy of reconstructed signal still reaches ≈96%. The work paves the way for efficient information processing of human–computer interactions and the Internet of Things.
Light‐Emitting Microinlaid Spots Produced through Lateral Phase Separation by Means of Simple Single‐Inkjet Printing
Authors: Park Byoungchoo , Park Jaewoo , Kim Wonsun , Na Seo Young , Huh Yoon Ho , Kim Mina , Choi Eun Ha
Published: May 2022

High‐performance solution‐processable light‐emitting diodes (LEDs) attract much research interest due to the very high complexity of conventional vacuum‐processed LEDs. A simple single‐inkjet‐printing process using a phase‐separable material combination is presented. With single‐inkjet printing of an ink containing semiconducting compounds on a phase‐separable insulating layer, convective and Marangoni flows in sessile droplets can produce microinlaid spots through the site‐selective etching of the insulating layer and the simultaneous self‐filling of the semiconductors in the etched vacancies. As a proof of concept, microinlaid organic LEDs (OLEDs) with a spatial resolution of ≈200 dpi in a phase‐separable poly(4‐vinylpyridine) layer without any conventional preformation of bank‐like structures are produced. The fabricated green microinlaid OLEDs exhibit excellent performance with maximum brightness of ≈13 000 cd m−2 and maximum efficiency of ≈14.2 cd A−1. Moreover, large‐area inkjet‐printed OLEDs are simply realized using the microinlaid spot arrays. These results demonstrate that the inkjet‐inlay structure is a promising candidate for high‐performance next‐generation solution‐processable LEDs.
Suppressing Glass‐Transition and Lithium‐Ions Migration in Hole Transport Layer by V2O5 Decorated Graphite Carbon Nitride Nanosheets for Thermally Stable Perovskite Solar Cells
Authors: Cao Wei , Zhang Jian , Lin Kaifeng , Li Junzhuo , Dong Yayu , Xia Debin , Fan Ruiqing , Yang Yulin
Published: May 2022

The undesired glass transition of 2,2’,7,7’‐tetrakis(N,N‐di‐p‐methoxyphenylamine)‐9,9’‐spirobifluorene (spiro‐OMeTAD) and the lithium‐ions migration are the intractable factors affecting the stability of perovskite solar cells (PSCs). Herein, the 2D graphite carbon nitride nanosheets (CNVx) with various loading masses of V2O5 are developed as additives for spiro‐OMeTAD to achieve stable and efficient PSCs. The optimized CNVx possesses quantitative and controllable oxidation ability to spiro‐OMeTAD under the inert atmosphere, yielding significantly improved conductivity and hole mobility of the modified hole transport layer (HTL) film. As a result, a power conversion efficiency (PCE) of 21.10% is obtained in the CNVx modified device with enhanced open‐circuit voltage of 1.114 V and fill factor of 0.80. Furthermore, the glass transition temperature suppression in the CNVx‐modified HTL film and effective Li+ ions capture significantly improve the stability of the unencapsulated device, which maintains 82% and 90% of the original PCE after aging at 85 °C in the N2 atmosphere and storing in an ambient atmosphere with a relative humidity of 40% for 720 h, respectively. These results provide a deep understanding of PSCs stability enhancement with 2D carbon nanosheets for realizing high‐performance PSCs.
HSCR: Hierarchical structured cluster routing protocol for load balanced wireless sensor networks
Authors: Gangwar Saumitra , Prasad Ikkurthi Bhanu , Yogita  , Yadav Satyendra Singh , Pal Vipin , Kumar Patra Sarat
Published: May 2022

The robustness of wireless sensor networks (WSNs) has made it a preferred choice for many applications. WSNs should perform the intended sensing task with a limited amount of energy. Clustering methodology is used to reduce sensor nodes' energy consumption and increase the network lifetime by organizing nodes into independent groups. In this article, a hierarchical structured cluster routing (HSCR) protocol based on the principle of an m‐way balanced tree has been proposed for multi‐hop intra‐cluster communication and offload the cluster head. It enhances the network performance by providing an underlying architecture that reduces the intra‐cluster communication distance and the amount of data sent to the cluster head. In the proposed HSCR protocol, an m‐way tree‐based hierarchical structure has been proposed in which balanced structure is formed within each cluster so that data aggregation is performed at each intermediate parent node. The proposed approach can be implemented over any communication protocol used in WSNs. Simulation results prove that the proposed algorithms outperform traditional clustering algorithms, LEACH and CT‐RPL, in terms of network stability, energy consumption, and network lifetime. Simulation results affirm that the proposed algorithms outperform traditional clustering algorithms, LEACH and CT‐RPL, in terms of network stability, energy consumption, average intra‐cluster communication distance and network lifetime by 105.32%, 49.23%, 14.98%, 109.31%, and 35.75%, 15.32%, 17%, 24.31%, respectively.
A phylogenetic approach to the study of the evolution of Hypermecaspididae (Olenida, Trilobita)
Authors: Monti Daniela S. , Tortello M. Franco , Confalonieri Viviana A.
Published: May 2022

Hypermecaspidinae (Trilobita; Olenidae) constitutes a monophyletic clade but its internal relationships are unknown and its phylogenetic position with respect to the rest of Olenida has recently been questioned. In order to propose a phylogenetic hypothesis, and to resolve the status of the group, a cladistic analysis of the hypermecaspidinids was performed. One hundred characters (28 quantitative and 72 qualitative) of holaspid morphology were coded for 30 taxa (18 Hypermecaspidinae). Two groups of analyses were performed considering the percentage of missing data. For each group of analyses, discrete partition was treated as totally unordered or as with some characters (describing intensity, position or shape of certain structures) ordered. The analyses were performed with TNT using maximum parsimony and implied weighting as optimality criteria. Hypermecaspididae constitutes a monophyletic family within Olenida, and is the sister group of pterocephaliids. In light of the present analysis, an emended diagnosis of the family is provided. The results suggest that ‘Tropidopyge’ broeggeri should be reassigned to Hypermecaspis. Hypermecaspidids would have originated in the late Furongian and rapidly diversified across different parts of the world in the Early Ordovician. With the exception of H. armata and H. chamarrensis, the species of Hypermecaspis have a proportionately large pygidium with a wide doublure and a distinct postaxial field. An evolutionary trend toward an increase in the size of these characters is observed in the genus. The cranidium shows a tendency toward enlargement of the glabella and the palpebral lobes, together with a narrowing of the interocular genae.
Phase Identification of Distribution Network Based on Phasor Angle Measurement
Authors: Li Fangshuo , Liu Lina , Cheng Zhijiong , Wang Tao , Qu Ming , Li Ruichao
Published: May 2022

Because of the crosstalk of neutral line signals in adjacent distribution transformers, the phase attribution relationship between users and transformer is not clear, which brings difficulties to the collection of users' electricity consumption information, file management, and power systems business development. Accordingly, this paper proposes a phase identification method for distribution network users based on dynamic phasor measurement, which can effectively identify all phase meter devices under the same station area. Firstly, considering that the signal on the power line contains complex frequency components and interference, the time‐varying phasor is approximated by the Taylor series. Secondly, by combining the discrete Fourier transform results of two adjacent data windows and calling the offline calculation matrix, accurate phasor measurements can be obtained. Phase shift processing is to obtain the phase angle of the bus line on the low‐voltage side of the transformer and the user at the same reporting time. In addition, the phase angle distortion caused by the impedance of the transmission line under different currents is also considered, so we make phase angle compensation to decrease the influence of the impedance of the line on the voltage phase angle. Simulation results and field experiments show that the proposed method can achieve a recognition success rate of 100% under frequency deviation conditions. Under the dynamic modulation and harmonic interference conditions, the recognition success rate could achieve 94.83% and 96.55%, respectively, it is much higher than that of the voltage correlation analysis method. © 2022 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.
Re‐evaluation of Ni/p‐GaN Schottky‐Barrier Height Based on Thermionic‐Emission‐Diffusion Theory
Authors: Mochizuki Kazuhiro , Ohta Hiroshi , Mishima Tomoyoshi
Published: May 2022

Reported hole mobility μ at room temperature was used to estimate the effective diffusion velocity VD related with the hole transport from the depletion‐layer edge to the potential minimum of Ni/p‐GaN Schottky‐barrier diodes (SBDs), revealing improper usages of the thermionic‐emission (TE) theory in previous reports. Based on the thermionic‐emission‐diffusion theory, the Schottky‐barrier height qΦB in the case μ = 32 ± 2 cm2/Vs was re‐evaluated to be 2.28 eV, which almost agreed with the reported qΦB determined from capacitance‐voltage measurements. The present result suggested that for p‐GaN SBDs, other qΦB values that had been determined from the TE theory should also be re‐evaluated. © 2022 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.
A Device for Visualizing Wi‐Fi Frames Using an LED Panel
Authors: Taniguchi Yoshiaki , Muto Kaito
Published: May 2022

In this letter, we propose a device that visualizes Wi‐Fi frames in a wireless LAN for beginners with little knowledge of networks. Our visualization device focuses on the nearest Wi‐Fi device and uses a blinking LED panel to convey the frames that are transmitted and received by that device. The blinking pattern and the color of the LED panel depend on the difference in the frame type between transmission and reception, thus allowing a user to intuitively understand what kind of frames are being sent and received. We implemented our proposed device using commercially available products and confirmed that it performs as expected. © 2022 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.
Forming an investigative opinion in digital forensics
Authors: Horsman Graeme
Published: May 2022

As we now see digital evidence play a role in many investigative scenarios, it is imperative that those seeking to rely upon it as part of criminal justice processes can do so, absent any concern regarding its validity. Interpreting the meaning of digital data and its potential value to a criminal inquiry as part of a digital forensic examination is a complex and multifaceted process requiring the practitioner to possess the relevant knowledge, experience, and insight needed to determine the case‐significance of a given data trace accurately. Erroneously interpreted data that is communicated to a client and subsequently relied upon can have far‐reaching consequences for all those involved in the investigative process. This work discusses the process of forming investigative opinions in digital forensic science examinations, what this means in practice, and the ways in which it can be achieved. Focus will be given to the process of forming an investigative opinion when underpinned through the reconstruction and testing of a suspect system/setup, with a formal three‐stage methodology for doing this outlined.

This article is categorized under:

Digital and Multimedia Science > Cybercrime Investigation
Carotid artery injury in endoscopic endonasal surgery: Risk factors, prevention, and management
Authors: Sharma Rahul K. , Irace Alexandria L. , Overdevest Jonathan B. , Gudis David A.
Published: May 2022

Objective

Endoscopic approaches for sinus and skull base surgery are increasing in popularity. The objective of this narrative review is to characterize risk factors for internal carotid artery injury in endoscopic endonasal surgery (EES), highlight preventative measures, and illustrate key management principles.

Data Sources

Comprehensive literature review.

Methods

Relevant literature was reviewed using PubMed/MEDLINE.

Results

Carotid artery injury in EES is rare, with most studies reporting an incidence below 0.1%. Anatomic aberrancies, wide dissection margins, as well as specific provider and hospital factors, may increase the risk of injury. Multidisciplinary teams, comprehensive preoperative imaging, patient risk assessment, and formal training in vascular emergencies may reduce the risk. Management protocols should emphasize proper visualization of the injury site, fluid replacement, rapid packing, angiography, and endovascular techniques to achieve hemostasis.

Conclusions

While EES is a relatively safe procedure, carotid artery injury is a devastating complication that warrants full consideration in surgical planning. Important preventative measures include identifying patients with notable risk factors and obtaining preoperative imaging. Multidisciplinary teams and management protocols are ultimately necessary to reduce morbidity and mortality.
Endoscopic endonasal approach to the craniovertebral junction
Authors: Halderman Ashleigh A. , Barnett Samuel L.
Published: May 2022

The surgical approach to lesions of the ventral craniovertebral junction (CVJ) has evolved significantly in the last several years with the advent of endoscopic skull base surgery. Differing pathologies of the CVJ can result in irreducible compression of the cervicomedullary region. The endoscopic endonasal approach lends itself well to this region due to the ventral location, and while there is a steep learning curve, is a safe and effective way to perform decompression of the cervicomedullary region. Herein, we discuss the anatomy of the CVJ, preoperative evaluation and surgical considerations, our surgical approach, complications, and outcomes.
Odontogenic sinusitis: A state‐of‐the‐art review
Authors: Craig John R.
Published: May 2022

Odontogenic sinusitis (ODS) is more common than historically reported, and is underrepresented in the sinusitis literature. ODS is distinct from rhinosinusitis in that it is infectious sinusitis from an infectious dental source or a complication from dental procedures, and most commonly presents unilaterally. ODS clinical features, microbiology, and diagnostic and treatment paradigms are also distinct from rhinosinusitis. ODS evaluation and management should generally be conducted by both otolaryngologists and dental providers, and clinicians must be able to suspect and confirm the condition. ODS suspicion is driven by certain clinical features like unilateral maxillary sinus opacification on computed tomography, overt maxillary dental pathology on computed tomography, unilateral middle meatal purulence on nasal endoscopy, foul smell, and odontogenic bacteria in sinus cultures. Otolaryngologists should confirm the sinusitis through nasal endoscopy by assessing for middle meatal purulence, edema, or polyps. Dental providers should confirm dental pathology through appropriate examinations and imaging. Once ODS is confirmed, a multidisciplinary shared decision‐making process should ensue to discuss risks and benefits of the timing and different types of dental and sinus surgical interventions. Oral antibiotics are generally ineffective at resolving ODS, especially when there is treatable dental pathology. When both the dental pathology and sinusitis are addressed, resolution can be expected in 90%–100% of cases. For treatable dental pathology, while primary dental treatment may resolve the sinusitis, a significant percentage of patients still require endoscopic sinus surgery. For patients with significant sinusitis symptom burdens, primary endoscopic sinus surgery is an option to resolve symptoms faster, followed by appropriate dental management. More well‐designed studies are necessary across all areas of ODS.
Haber’s Cooperation with BASF
Authors: Johnson Benjamin
Published: May 2022

Parallel to the experiments for the 1908 publication on ammonia synthesis, Haber continued to work on the electric arc with Adolf König. At the time, BASF was stagnant; its ability to innovate had become too dependent on external academic research. In December of 1907, Carl Engler, a BASF Board member, brought the company into contact with Haber in an attempt to remedy the problem.
Terminology
Authors: Johnson Benjamin
Published: May 2022

In Parts I and 10.1007/978-3-030-85532-1_Part2, the scientific breakthrough of ammonia synthesis was described in terms of a confluence of factors leading to an arena of research mature enough for advancement—it is a dynamic encapsulated in the concept of The Haze.
The Scientification of Agriculture
Authors: Johnson Benjamin
Published: May 2022

It may seem that ammonia synthesis was a scientific triumph for chemistry that also had unexpected consequences for agriculture, much in line with Max Planck’s dictum: “Understanding must precede application.” However, in historical hindsight things often happen just the opposite: in the case of ammonia synthesis, practice and experience preceded theory. Without observations from agriculture and a general understanding of the role of fertilizer—and of nitrogen and the nitrogen cycle in particular—certain essential chemical insight would not have been considered valuable.
The Haze: Interdependencies in Science
Authors: Johnson Benjamin
Published: May 2022

The discussion of the Haze so far has only peripherally included the bifurcation of science into “normal” and “crisis.” This perspective has been useful in illustrating some aspects of scientific research. However, the complexity of the Haze along with the nature of paradigms may have already made it apparent that the notion of a parallel existence of two distinct kinds of science is too simplified, especially when considering modern mathematically based theories and the advanced technology needed for the production of supporting experimental evidence. The success of the scientific endeavor depends on an interdependence of “normal science” and multiple paradigms so that there is no clear separation between fact-gathering and “times of crisis” in science leading to paradigm change (whatever form the latter may take). Both are always present in some form and to some degree. The consideration of an example of modern research provides a succinct illustration.
The Scientific Breakthrough (1903–1908)
Authors: Johnson Benjamin
Published: May 2022

So far, we have discussed a confluence of factors leading to the ability to understand and solve the practical problem of ammonia synthesis. Research in agricultural science led to an awareness of the need for a synthetic source of fixed nitrogen, while developments in organic chemistry helped lead to the infrastructure, capital, and expertise of the German chemical industry. Further conceptual steps in the natural sciences gave rise to the discipline of physical chemistry and a new theoretical framework for chemical reactions. The possibility of synthesizing ammonia from the elements was now plausible, meaning a solution was on the horizon. In 1898, William Crookes’ message to the world on the importance of ammonia synthesis for the production of foodstuffs not only framed the looming humanitarian crisis but also made its economic potential clear. All that was left to determine were the conditions under which ammonia could be synthesized.
Reflections on Scientific Discovery and The Haze
Authors: Johnson Benjamin
Published: May 2022

The presentation of the confluence of factors has often included a modern perspective. Here I will touch on some consequences of Haber’s breakthrough before reviewing aspects important to the next two parts of the book.
A novel tool to enhance the lubricant efficiency on induction heat-assisted incremental sheet forming of Ti-6Al-4 V sheets
Authors: Li Weining , Essa Khamis , Li Sheng
Published: May 2022

For heat-assisted single point incremental sheet forming (SPIF) works of Ti-6Al-4 V sheets, the use of lubricant has shown significant effects on surface quality and geometric accuracy at higher temperatures. Molybdenum disulphide (MoS2) is a common lubricant widely used in SPIF works, however, it usually indicates ineffective performance at high temperatures. This article has studied different lubricants of MoS2 lubricants and proposed a novel mixture of MoS2 to provide better surface quality and improve geometric accuracy. A forming tool with a ball-roller and water channel was designed to enable the MoS2 mixture to pass through the tool tip, allowing easy application of the lubricant on the localised area and reduce the thermal expansion on the ball-roller. Surface roughness analysis has revealed that the water-cooling MoS2 mixture performed well in reducing friction effects and achieved better geometric accuracy. Forming forces measurements, scanning electron microscope (SEM), energy-dispersive X-ray analysis (EDX) and micro-hardness tests also indicated that a higher strain hardening behaviour was detected for the water-cooling MoS2 mixture.