bluuebunny/crossref_metadata_2025 huggingface dataset:
Finite element simulation of chip formation coupled with process dynamics
Authors: Aurich J C , Piendl S
Published: December 2006

The vibrations occurring in the machining process affect the component surface and the production quality. For improved process examination, the three-dimensional finite element method (FEM) simulation of the chip formation is illustrated using the example of longitudinal surface turning while taking the process dynamics into account. Owing to the tool holder and the component with the clamping device, a system limit is defined with a flexibility which will be determined through experiments. The dynamics of the machine tool are illustrated with the FEM using simplified substitute models and coupled to the finite element model of the chip formation. As a result, in addition to the dynamics of the machine tool, the complex mechanisms of the chip formation resulting from the major deformations and heating are also approximately taken into account through the simulation of the chip formation. The results include not only the machining forces and the temperatures in the component and chips, but also determination of the movements of the component and tool holder, and with them the illustration of the vibrations.
A fresh approach to cyclic manufacturing
Authors: Sharma S , Goyal S K
Published: December 2006

A job shop usually deals with the manufacture of a wide variety of products. Often, it adopts the production of several items in a common cycle time. A certain portion of the cycle time is idle. In the literature, inadequate attention has been given to the non-productive time during a cycle. In this paper, an approach of reducing the production rate of the product is proposed. Cost reduction as a result of reducing the production rate is demonstrated.
Monitoring and processing the acoustic emission signals from the friction-stir-welding process
Authors: Soundararajan V , Atharifar H , Kovacevic R
Published: December 2006

This paper discusses the detection and analysis of the acoustic emission (AE) signals to investigate the possibility of applying the AE technique for the in-process monitoring of the friction-stir-welding process. Tests are carried out for joining similar and dissimilar metals using a high-speed rotating tool under various rotational speeds and traverse speeds and for different tool penetration depths. The results of fast Fourier transform show that the amplitude of the AE signal in the frequency domain is sensitive to the change in the depth of penetration of the tool. Signals in certain frequency ranges disappear when the tool loses contact with the workpiece during the process. Discrete wavelet transform indicates significant sudden changes in the decomposed signal in the lower frequency ranges (higher levels) when the shoulder makes contact with or detaches itself from the workpieces. By identifying the frequencies during the process and analysing the wavelet decomposed signals in various levels or frequency bands, it is possible to monitor effectively the transient welding state and to identify quickly 2the process changes.
State-of-the-art in lean design engineering: A literature review on white collar lean
Authors: Baines T , Lightfoot H , Williams G M , Greenough R
Published: December 2006

Lean is usually associated with the ‘operations’ of a manufacturing enterprise; however, there is a growing awareness that these principles may be transferred readily to other functions and sectors. The application to knowledge-based activities such as engineering design is of particular relevance to UK plc. Hence, the purpose of this study has been to establish the state-of-the-art, in terms of the adoption of Lean in new product development, by carrying out a systematic review of the literature. The authors' findings confirm the view that Lean can be applied beneficially away from the factory; that an understanding and definition of value is key to success; that a set-based (or Toyota methodology) approach to design is favoured together with the strong leadership of a chief engineer; and that the successful implementation requires organization-wide changes to systems, practices, and behaviour. On this basis it is felt that this review paper provides a useful platform for further research in this topic.
Influence of plastic deformations on growth of subsurface rolling contact fatigue cracks in railway wheels
Authors: Lansler E , Ekberg A , Kabo E , Andersson H
Published: December 2006

A subsurface rolling contact fatigue crack in a railway wheel is studied. Stress and strain fields are evaluated by elasto-plastic finite-element simulations. The robustness and validity of the numerical model are investigated. A suitable measure to characterize crack propagation is then sought. Numerical results show that the effect of crack tip plasticity is small for cases studied, indicating that linear elastic fracture mechanics approaches are applicable. Further, the magnitudes of the stress intensity factor in mode I, KI, are negative implying crack closure. Motivated by these findings, the stress intensity factor range in mode II, Δ KII, is employed as a measure of crack propagation. Finally, studies are carried out to quantify the effects of altered contact load conditions and crack face friction.
Non-linearity evaluation and reduction for serial manipulators
Authors: Herman P
Published: December 2006

In this paper, a controller for evaluation and improvement of dynamic properties of a serial manipulator is presented. It is shown that on the basis of the first-order equations of motion expressed in terms of the generalized velocity components (GVCs), it is possible to propose the controller in order to determine coupling effects appearing during the manipulator motion. The GVC velocity controller contains the manipulator dynamics and offers an interesting insight into the manipulator dynamics. Performance of the GVC controller is illustrated in simulation study on a three-degrees-of-freedom spatial manipulator.
Rejecting the phonetics/phonology split
Authors: Lindblom Björn
Published: December 2006

Structuralism

One of the most significant developments of linguistics in the past century is undoubtedly the introduction of the distinction between form and substance. The adoption of this dichotomy was a crucial part of the launching of structural linguistics. Although today these Saussurean terms may have an obsolete ring to them, it is nonetheless true that this distinction still enjoys the status of ‘inescapable’ cornerstone of linguistic methodology. For the linguist the primary focus is on structure whereas the study of the way this structure is actualized in speaking and listening falls in the domain of performance, behavioral research and experimental phonetics.
A Limited Role for p21Cip1/Waf1 in Maintaining Normal Hematopoietic Stem Cell Functioning
Authors: van Os Ronald , Kamminga Leonie M. , Ausema Albertina , Bystrykh Leonid V. , Draijer Deanna P. , van Pelt Kyrjon , Dontje Bert , de Haan Gerald
Published: December 2006

Several studies have suggested that the cyclin-dependent kinase (CDK) inhibitor p21 plays a crucial role in regulating hematopoietic stem and progenitor pool size. To allow assessment of long-term stem cell functioning in vivo, we have backcrossed a p21 null allele to C57BL/6 (B6) mice, the most commonly used mouse strain in hematopoietic stem cell research. In various in vitro assays, the homozygous deletion of the p21 allele did not affect the number of hematopoietic cells in B6 mice. Furthermore, the competitive repopulation ability was not different between p21-deficient and wild-type stem cells from both young and aged (20-month-old) mice. These results show that p21 is not essential for regulation of stem cell number in steady state. When proliferative stress was applied on p21-deficient stem cells by serial transplantation of 1,500 Lin−Sca-1+c-kit+ (LSK) cells, again no detrimental effect was observed on cobblestone area-forming cell (CAFC) frequency and competitive repopulating ability. However, when bone marrow cells from mice that received 2 Gy of irradiation were transplanted, p21 deficiency resulted in a more than fourfold reduction in competitive repopulation index. Finally, we did not find major differences in cell cycle status and global gene expression patterns between LSK cells from p21-deficient and wild-type mice. Our findings indicate that the background of mice used for studying the function of a gene by genetic modification may determine the outcome. Cumulatively, our data fail to support the notion that p21 is essential for stem cell function during steady-state hematopoiesis, but may be relatively more important under conditions of cellular stress.

Disclosure of potential conflicts of interest is found at the end of this article.
Development of a low-cost dynamic filter immersed in activated sludge system
Authors: Chen G.H. , Pang S.K.
Published: December 2006

Wasted non-woven material was employed to develop a dynamic filter immersed in bioreactor (DFIB) to treat low strength wastewater. A bench-scale DFIB was investigated to evaluate its feasibility. The maximum permeate flux of this innovative DFIB was more than 3 times greater than that of a conventional non-woven filter and even similar to that of a mesh filter, while the effluent quality of the developed DFIB in terms of turbidity, SS, and COD was better than that of a mesh filter, which were below 1.5 NTU, 3 and 35 mg/L, respectively. Such effluent quality with appropriate disinfection could meet the requirement for wastewater reuse for various urban usages. The acceptable MLSS level was identified not greater than 5 g/L in order to secure the effluent quality, when the maximum permeate flux of 1.5 m3/m2·day and daily backwash are applied. The large permeate flux rate and relatively high MLSS level of the DFIB can achieve cost-effective treatment of low strength wastewater.
Factors affecting bromate removal capacity of zerovalent iron packed columns
Authors: Fan C. , Chan C.H. , Xie L. , Shang C.
Published: December 2006

In a series of column experiments lasting for approximately 1500 pore volume, the effects of operational factors (flow rates, sand admixtures) and water quality factors (concentrations of DO, sulfate, phosphate and bicarbonate) on bromate removal capacity of zerovalent iron were investigated. The bromate removal capacity, obtained from migration of concentration profiles, was observed to decrease with increases in flow rate. In the case that 20 wt-% iron was replaced by sands, the bromate removal capacity increased, but, on the contrary, the bromate removal capacity inevitably decreased when the weight percentage was increased by two times. Dissolved oxygen played a minor role in decreasing the bromate removal capacity, this decreasing effect only prevailed near the proximal end of depassivating irons. The bromate removal capacity increased in the presence of 100 mg/L sulfate concentration but decreased when the sulfate concentration further increased. When comparing the effect on removal capacity for phosphate and sulfate, the inhibiting effect of phosphate on the bromate removal capacity was larger. Lastly, the removal capacity increased with increasing bicarbonate concentration, which may due to the formation of aqueous complexes.
Stability of inorganic arsenic species in simulated raw waters with the presence of NOM
Authors: Liu G.J. , Zhang X.R. , Jain J. , Talley J.W. , Neal C.R.
Published: December 2006

Effect of natural organic matter (NOM) on the stability of inorganic arsenic species in simulated raw water was examined at circumneutral pH. An ion chromatography–inductively coupled plasma mass spectrometry system was used for simultaneous determination of As(III) and As(V). A reduction of arsenate (As(V)) to arsenite (As(III)) was observed in the unfiltered simulated raw waters (USW). The As(V) reduction to As(III) did not occur in the simulated waters that passed through a 0.2 μm membrane (FSW). Microorganism activities is probably the major reason causing As(V) reduction in the USW. In the FSW without NOM, As(III) tended to be oxidized into As(V). The addition of 0.036 mM of Fe(II) significantly facilitated the oxidation. The presence of 10 mg/L Suwannee River NOM as C inhibited As(III) oxidation no matter whether Fe(II) existed or not. The experimental results suggest that NOM can mediate distribution of inorganic arsenic species in water, thus it is an important factor controlling the mobility and toxicity of arsenic in drinking water.
Nutrients removal mechanisms in high rate algal pond treating rural domestic sewage in East China
Authors: Zhou Q. , He S.L. , He X.J. , Huang X.F. , Picot B. , Li X.D. , Chen G.
Published: December 2006

This study focused on the evaluation of performance and mechanisms of a high-rate algal pond system (HRAP System) in nitrogen and phosphorus removal for rural domestic sewage treatment. A pilot scale HRAP System was located at Yangzhu Village, Jiangsu Province, east China, with treatment processes including a septic tank, two stages of HRAPs and an aquatic pond. Results showed that the HRAP System had a good performance in nutrient removal, especially in NH+4-N removal. Total removal efficiencies of COD, TN, NH+4-N and TP were 80, 51.8, 90.2 and 52.1%, respectively. About 61.6% of NH+4-N in the 1st-stage HRAP and 70.9% in the 2nd-stage HRAP were transformed into NO−3-N and NO2−-N through nitrification, and the nitrogen losses via ammonia volatilization was only 2.7% (for 1st-stage HRAP) and 8.8% (for 2nd-stage HRAP). The other 35.7% and 20.3% of NH+4-N removal were achieved by algae assimilation respectively. About 98.0% (for 1st-stage HRAP) and 84.8% (for 2nd-stage HRAP) removal of TN were attributed to algae sedimentation, while those through ammonia volatilization were only 2.0% (for 1st-stage HRAP) and 15.4% (for 2nd-stage HRAP), respectively. Therefore, the main mechanisms of NH+4-N removal in HRAP were nitrification and algae assimilation, and TN was mainly removed by algae sedimentation. About 50.7% (for 1st-stage HRAP) and 53.1% (for 2nd-stage HRAP) of phosphorus in the deposit were organic phosphates respectively, only 20.7% and 27.7% were calcium-bound and magnesium-bound phosphates. The removal mechanism of TP in HRAP could be mainly attributed to algae assimilation in forms of organic phosphate, and chemical precipitation in forms of calcium-bound and magnesium-bound.
Pilot study for the potential application of a shortcut nitrification and denitrification process in landfill leachate treatment with MBR
Authors: An K.J. , Tan J.W. , Meng L.
Published: December 2006

An advanced nitrogen removal pilot study was performed in China's Xia Ping Landfill Leachate Treatment Plant to undertake shortcut nitrification and denitrification with the Membrane Bio-reactor (MBR) process. It was found that the MBR process used 25% less of the oxygen and 40% less of the external carbon sources, compared to the conventional nitrification and denitrification process. The key feature of the MBR process is that it provides an environment more favorable for ammonia oxidation bacterium (AOB) than for nitrite oxidation bacterium (NOB) through controlling loading, pH, temperature, dissolved oxygen concentration (DO), and NH3 inhibition. Optimum operating condition was examined through continuous running of the pilot MBR, and it was found that a minimum HRT of 4.3 days and maximum ammonia loading of 0.6 kg N- NH4+ m3.d with pH 7–8.5, temperature 25–30 °C, and DO at 2 mg/L is favorable to AOB. Kinetic study was conducted to identify the characteristic of the microorganisms in the system. Measured Ks and μA,max of MBR sludge was 19.65 mg NH4-N/L (Temperature 25 °C, pH 8.5) and 0.26 d−1, respectively.
Effect of irrigation with reclaimed water on crops and health risk assessment
Authors: Zhao Q.L. , Zhang J.N. , You S.J. , Wang S.H. , Wang L.N.
Published: December 2006

Irrigation with tertiary effluent, secondary effluent, and raw wastewater (sewage) were studied with tap water irrigation as the control. The effects of the irrigations on the qualities of three testing crops: cucumber, celery cabbage and maize were investigated. The contents of residual chloride ion, phosphate, nitrate, nitrite, and residual heavy metals in these irrigated crops were also examined. The results showed that the secondary and tertiary effluent had no significant effects on the crop qualities. However, irrigation with the sewage could lead to increase parts of nutrient components in the crops. Irrigation with the sewage caused accumulation of nitrate and heavy metals in the crops, indicating that sewage was not suitable for irrigation. The risk assessment results suggested that the health risk of the irrigations using sewage and secondary effluent exceeded the maximum acceptable risk level. Comparatively, the risk in the tertiary effluent irrigation was much lower than the acceptable level.
Risk factors associated with short-term outcome and development of perioperative complications in dogs undergoing surgery because of gastric dilatation-volvulus: 166 cases (1992–2003)
Authors: Beck Jennifer J. , Staatz Andrew J. , Pelsue Davyd H. , Kudnig Simon T. , MacPhail Catriona M. , Seim Howard B. , Monnet Eric
Published: December 2006

Objective—To evaluate risk factors associated with death and development of perioperative complications in dogs undergoing surgery for treatment of gastric dilatation-volvulus (GDV).

Design—Retrospective case series.

Animals—166 dogs.

Procedures—Records of dogs with confirmed GDV that underwent surgery were reviewed. Logistic regression was performed to identify factors associated with development of complications (ie, hypotension, arrhythmias, gastric necrosis necessitating gastrectomy, disseminated intravascular coagulation, peritonitis, sepsis, postoperative dilatation, postoperative vomiting, and incisional problems) and with short-term outcome (ie, died vs survived to the time of suture removal).

Results—Short-term mortality rate was 16.2% (27/166). Risk factors significantly associated with death prior to suture removal were clinical signs for > 6 hours prior to examination, combined splenectomy and partial gastrectomy, hypotension at any time during hospitalization, peritonitis, sepsis, and disseminated intravascular coagulation. Partial gastrectomy was not a significant risk factor for death but was for peritonitis, disseminated intravascular coagulation, sepsis, and arrhythmias. Age, gastrectomy, and disseminated intravascular coagulation were risk factors for development of hypotension. Use of a synthetic colloid or hypertonic saline solution was associated with a significantly decreased risk of hypotension.

Conclusions and Clinical Relevance—Results suggest that the prognosis for dogs undergoing surgery because of GDV is good but that certain factors are associated with an increased risk that dogs will develop perioperative complications or die.
A Female in Her 50s With Caseating Mitral Annulus Calcification
Authors: Minga Iva , Appadurai Vinesh , Rigolin Vera
Published: March 2024

This case report describes a diagnosis of caseating mitral annulus calcification in a female patient with a history of peritoneal dialysis who presented with confusion and disorientation.
Entrustable Professional Activities in Surgery
Authors: Montgomery Kelsey B. , Mellinger John D. , Lindeman Brenessa
Published: March 2024

Importance

Entrustable professional activities (EPAs) compose a competency-based education (CBE) assessment framework that has been increasingly adopted across medical specialties as a workplace-based assessment tool. EPAs focus on directly observed behaviors to determine the level of entrustment a trainee has for a given activity of that specialty. In this narrative review, we highlight the rationale for EPAs in general surgery, describe current evidence supporting their use, and outline some of the practical considerations for EPAs among residency programs, faculty, and trainees.

Observations

An expanding evidence base for EPAs in general surgery has provided moderate validity evidence for their use as well as practical recommendations for implementation across residency programs. Challenges to EPA use include garnering buy-in from individual faculty and residents to complete EPA microassessments and engage in timely, specific feedback after a case or clinical encounter. When successfully integrated into a program’s workflow, EPAs can provide a more accurate picture of residents’ competence for a fundamental surgical task or activity compared with other assessment methods.

Conclusions and Relevance

EPAs represent the next significant shift in the evaluation of general surgery residents as part of the overarching progression toward CBE among all US residency programs. While pragmatic challenges to the implementation of EPAs remain, the best practices from EPA and other CBE assessment literature summarized in this review may assist individuals and programs in implementing EPAs. As EPAs become more widely used in general surgery resident training, further analysis of barriers and facilitators to successful and sustainable EPA implementation will be needed to continue to optimize and advance this new assessment framework.
Phosphorylation of TG‐interacting factor 1 at carboxyl‐terminal sites in response to insulin regulates adipocyte differentiation
Authors: Chang Yu‐Hao , Tseng Yu‐Hua , Wang Ju‐Ming , Tsai Yau‐Sheng , Liu Xin‐Lei , Huang Huei‐Sheng
Published: March 2024

TG‐interacting factor 1 (TGIF1) contributes to the differentiation of murine white preadipocyte and human adipose tissue‐derived stem cells; however, its regulation is not well elucidated. Insulin is a component of the adipogenic cocktail that induces ERK signaling. TGIF1 phosphorylation and sustained stability in response to insulin were reduced through the use of specific MEK inhibitor U0126. Mutagenesis at T235 or T239 residue of TGIF1 in preadipocytes led to dephosphorylation of TGIF1. The reduced TGIF1 stability resulted in an increase in p27kip1 expression, a decrease in phosphorylated Rb expression and cellular proliferation, and a reduced accumulation of lipids compared to the TGIF1‐overexpressed cells. These findings highlight that insulin/ERK‐driven phosphorylation of the T235 or T239 residue at TGIF1 is crucial for adipocyte differentiation.
Evaluation of the availability of single‐position treatment with a rotating gantry and the validity of deformable image registration dose assessment for pancreatic cancer carbon‐ion radiotherapy
Authors: Miyasaka Yuya , Kawashiro Shohei , Lee Sung Hyun , Souda Hikaru , Ichikawa Mayumi , Chai Hongbo , Ishizawa Miyu , Ono Takuya , Sato Hiraku , Iwai Takeo
Published: March 2024

Background

This study aimed to evaluate the clinical acceptability of rotational gantry‐based single‐position carbon‐ion radiotherapy (CIRT) to reduce the gastrointestinal (GI) dose in pancreatic cancer. We also evaluated the usefulness of the deformable image registration (DIR)‐based dosimetry method for CIRT.

Material and methods

Fifteen patients with pancreatic cancer were analyzed. The treatment plans were developed for four beam angles in the supine (SP plan) and prone (PR plan) positions. In the case of using multiple positions, the treatment plan was created with two angles for each of the supine and prone position (SP + PR plan). Dose evaluation for multiple positions was performed in two ways: by directly adding the values of the DVH parameters for each position treatment plan (DVH sum), and by calculating the DVH parameters from the accumulative dose distribution created using DIR (DIR sum). The D2cc and D6cc of the stomach and duodenum were recorded for each treatment plan and dosimetry method and compared.

Results

There were no significant differences among any of the treatment planning and dosimetry methods (p > 0.05). The DVH parameters for the stomach and duodenum were higher in the PR plan and SP plan, respectively, and DVH sum tended to be between the SP and PR plans. DVH sum and DIR sum, DVH sum tended to be higher for D2cc and DIR sum tended to be higher for D6cc.

Conclusion

There were no significant differences in the GI dose, which suggests that treatment with a simple workflow performed in one position should be clinically acceptable. In CIRT, DIR‐based dosimetry should be carefully considered because of the potential for increased uncertainty due to the steep dose distributions.
Dual‐branch feature fusion S3D V‐Net network for lung nodules segmentation
Authors: Xu Xiaoru , Du Lingyan , Yin Dongsheng
Published: March 2024

Background

Accurate segmentation of lung nodules can help doctors get more accurate results and protocols in early lung cancer diagnosis and treatment planning, so that patients can be better detected and treated at an early stage, and the mortality rate of lung cancer can be reduced.

Purpose

Currently, the improvement of lung nodule segmentation accuracy has been limited by his heterogeneous performance in the lungs, the imbalance between segmentation targets and background pixels, and other factors. We propose a new 2.5D lung nodule segmentation network model for lung nodule segmentation. This network model can well improve the extraction of edge information of lung nodules, and fuses intra‐slice and inter‐slice features, which makes good use of the three‐dimensional structural information of lung nodules and can more effectively improve the accuracy of lung nodule segmentation.

Methods

Our approach is based on a typical encoding‐decoding network structure for improvement. The improved model captures the features of multiple nodules in both 3‐D and 2‐D CT images, complements the information of the segmentation target's features and enhances the texture features at the edges of the pulmonary nodules through the dual‐branch feature fusion module (DFFM) and the reverse attention context module (RACM), and employs central pooling instead of the maximal pooling operation, which is used to preserve the features around the target and to eliminate the edge‐irrelevant features, to further improve the performance of the segmentation of the pulmonary nodules.

Results

We evaluated this method on a wide range of 1186 nodules from the LUNA16 dataset, and averaging the results of ten cross‐validated, the proposed method achieved the mean dice similarity coefficient (mDSC) of 84.57%, the mean overlapping error (mOE) of 18.73% and average processing of a case is about 2.07 s. Moreover, our results were compared with inter‐radiologist agreement on the LUNA16 dataset, and the average difference was 0.74%.

Conclusion

The experimental results show that our method improves the accuracy of pulmonary nodules segmentation and also takes less time than more 3‐D segmentation methods in terms of time.
SCADA based common bus regenerative control of PMSM drive for industrial application
Authors: Baranidharan M. , Raja Singh R.
Published: March 2024

The emerging trend in sustainable industrial processes focuses on energy‐efficient drives to enhance performance in both intermediate and continuous operating conditions. For decades, researchers have focused on permanent magnet synchronous machines (PMSM) for industrial applications in order to retain consistency in performance and efficiency under wide speed ranges. Common bus regenerative control is an energy‐efficient method used in industrial systems to manage power flow between multiple devices on a shared DC bus. It captures and reuses excess energy generated during braking/deceleration, reducing waste and improving overall system efficiency. The experimental behavior of the drive scheme has been observed as per the standards of the laboratory. In this article, regenerative control of a PMSM drive is using the voltage vector control (VVC+) technique and the SCADA based condition monitoring for the PMSM drive system is integrated to supervise the parameters including current, voltage, power, speed, torque, and temperature under dynamic operating conditions. As a primary step of implementing the drive condition monitoring is carried out through Danfoss's motion control tool software. Further, the SCADA control system is interfaced to FC302 PMSM drive through RS485 Modbus communication to extract the necessary electrical attributes and monitor the same.
Erythrocyte‐Derived Bioactive Nanovesicles Reverse the Immunosuppressive Function of Adenosine for Tumor Photoimmunotherapy
Authors: Sun Jiuyuan , Liu Yiqiong , Zhao Yuge , Yin Weimin , Yang Zichen , Chang Jiao , Huang Li , Chen Shiyu , Zhi Hui , Xue Liangyi , Zhang Xiaoyou , Dong Haiqing , Li Yongyong
Published: March 2024

Adenosine has garnered significant attention as a potential target for overcoming tumor immune evasion. It exacerbates the immunosuppressive tumor microenvironment (TME) by incapacitating various protective immune cells. However, inhibitors targeting adenosine receptors are limited by incomplete blockade effects and off‐target toxicity, necessitating the exploration of more effective strategies. Inspired by the native biologic function of adenosine deaminase (ADA) in hydrolyzing adenosine, a bioactive catalytic nanovesicle (ENV@FeS) is designed to reverse adenosine immunosuppressive function. The nanovesicle is constructed through the serial extrusion of erythrocytes abundant with ADA, coupled with the synthesis of FeS complex in situ using Fe2+ in erythrocytes via H2S gas introduction. Notably, the bioactive nanovesicles not only promote tumor targeting and induce immunogenic cell death by the FeS‐induced photothermal effect, but also hinder the adenosine pathway by metabolizing adenosine into immunopotentiator inosine, further boosting antitumor immunity. In vivo, ENV@FeS efficiently increases the infiltration of cytotoxic T lymphocytes and M1 macrophages while reducing the production of regulatory T cells and myeloid‐derived suppressor cells, resulting in significant inhibition of tumor growth. Together, the biomimetic nanovesicle‐mediated adenosine metabolic regulation, in synergy with photothermal therapy, leads to a marked improvement in the immunogenic TME and enhances the therapeutic efficacy of photoimmunotherapy.
Metal‐Organic Framework‐Based Electrocatalysts for Acidic Water Splitting
Authors: Zhou Shenghao , Shi Lei , Li Yanzhe , Yang Tao , Zhao Shenlong
Published: March 2024

The proton exchange membrane water electrolysis system has long been considered a promising technique for the generation of hydrogen owing to its high electrolytic efficiency, reliability, and quick response to renewable energy sources. At present, noble metals and their oxides (e.g., Pt, IrO2, and RuO2) are widely used as high active electrocatalysts for accelerating the conversion efficiency of the water electrolysis process, especially in acidic media. Nevertheless, the scarcity and instability seriously impede their large‐scale application in practice. In the past years, metal‐organic frameworks (MOFs) have proven to be an ideal platform for designing efficient and cost‐effective electrodes due to their unique physicochemical properties. In this review, the fundamental catalytic mechanisms of hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in acidic media are discussed first. Then, design strategies and advanced characterizations for MOF‐based water‐splitting catalysts are summarized. Finally, the recent research advances of MOF‐based electrocatalysts for HER and OER in acidic electrolytes, along with current challenges and future opportunities, are provided.
Strengthening d‐p Orbital‐Hybridization via Coordination Number Regulation of Manganese Single‐Atom Catalysts Toward Fast Kinetic and Long‐Life Sodium–Sulfur Batteries
Authors: Li Zhiqiang , Chen Xing , Yao Ge , Wei Lingzhi , Chen Qianwang , Luo Qiquan , Zheng Fangcai , Wang Hui
Published: March 2024

The practical application of room‐temperature sodium‐sulfur (RT Na–S) batteries is blocked by the notorious shuttle effect of sodium polysulfides (NaPSs) and sluggish refox reaction kinetics. Single‐atom catalysts (SACs) have been widely studied for boosting the energy storage performance of RT Na‐S batteries. Nevertheless, the catalytic centers of SACs reported so far have focused mainly on symmetrical metal–N4 structures, which offer weak bonding affinity toward polar NaPSs, leading to detrimental shuttle effect and sluggish sulfur conversion kinetics. Herein, a novel asymmetrical Mn–N2 structure is implanted into nitrogen‐doped carbon nanofibers (Mn‐N2/CNs) through thermal NH3 etching of a symmetrical Mn–N2O2 structure. The Mn–N2 structure promotes the bonding affinity and catalytic conversion of NaPSs due to the strengthened d‐p orbital‐hybridization between the d orbital of Mn in the Mn–N2 structure and the p orbital of S in NaPSs. Consequently, Mn‐N2/CNs@S achieves a high capacity of 458 mAh g−1 at 3.0 C with a capacity decay of 0.23% over 2300 cycles. This work offers a promising pathway for regulating the coordination number of SACs with strengthened d‐p orbital‐hybridization for high‐performance RT Na–S batteries.
Removing Cadmium Impurities from Cation‐Exchange‐Derived CuInSe2/CuInS2 Nanorods for Enhanced Infrared Emission and Photodetection
Authors: Portniagin Arsenii S. , Sergeev Aleksandr A. , Sergeeva Kseniia A. , Wang Shixun , Li Zhuo , Ning Jiajia , Chan Christopher C. S. , Kershaw Stephen V. , Zhong Xiaoyan , Wong Kam Sing , Rogach Andrey L.
Published: March 2024

Metal chalcogenide nanocrystals with variable composition and shape can conveniently be produced using cation exchange synthesis; however, the presence of cation‐containing ligands inherited from the starting material often results in contamination of the final product. To address this issue, a two‐step ligand replacement strategy is developed to fabricate CuInSe2/CuInS2 nanorods from CdSe/CdS nanorods via removal of Cd‐phosphonates from an intermediate Cu2‐xSe/Cu2‐xS phase used in the cation exchange conversion. This synthetic approach furnishes CuInSe2/CuInS2 nanorods with cadmium content below 1 at.%, and high photoluminescence quantum yields reaching 40% in the near‐infrared spectral range. Transient absorption studies reveal that the band alignment in the CuInSe2/CuInS2 heterostructure features a quasi‐type II character, with an electron localized in the core and a hole wavefunction spread over the entire nanorod. The efficient passivation of the core and the reduced Cd content leads to excitonic emission with full width at half maximum down to 110 meV, superimposed with a broad emission band from copper‐induced defects. Field‐effect transistors based on cadmium‐free CuInSe2/CuInS2 nanorods show two orders of magnitude lower noise current density compared with the cadmium‐rich devices. The responsivity and specific detectivity of these devices reach 230 mA W−1 and 108 Jones, respectively, under near‐infrared excitation at room temperature.
The Effect of Self‐Assembled Bridging Layer on the Performance of Pure FAPbI3‐Based Perovskite Solar Cells
Authors: Zhang Yang , Kong Tengfei , Liu Yinjiang , Liu Xufu , Liu Wenli , Saliba Michael , Bi Dongqin
Published: March 2024

Pure FAPbI3‐based, with FA being formamidinium, perovskite solar cells (PSCs) have garnered worldwide recognition for their exceptional efficiency. However, the phase stability of FAPbI3 is still a big obstacle in this area, because the ordinary strategy using MA+, Br−, Cs+ to stabilize α‐FAPbI3 phase can cause the bandgap change and ion migration. Herein, a new strategy is introduced to improve the α‐FAPbI3 phase stability by using a self‐assembled bridging layer at the buried interface of FAPbI3 perovskite in the n–i–p solar cell structure. A series of multidentate bisphosphonic acid molecules are screened and demonstrate that etidronic acid (EA) with the smallest steric hindrance behaves the best. The four P‐OH groups can first form multidentate anchors on SnO2 while the remaining unanchored ─OH and P═O groups can form strong interaction between I− and Pb2+. Thus, a strong and stable bridging layer is formed, which greatly increases the energy barrier of phase transition of FAPbI3. As a result, the pure FAPbI3‐based (MA+, Br+, Cs+‐free system) n–i–p device reached an impressive power conversion efficiency of 24.2% with good stability. Furthermore, the strong interaction between EA and Pb2+ can greatly reduce lead leakage in harsh conditions.
Scalable Synthesis of High‐Quality Ultrathin Ferroelectric Magnesium Molybdenum Oxide
Authors: Zhang Xingxing , Cheng Mo , Dai Jiuxiang , Yang Qianqian , Zhang Ye , Dong Baojuan , Tao Xinwei , Zou Jingyi , Jin Zhitong , Liu Feng , Wu Zhenghan , Hu Xianyu , Zheng Zemin , Shi Zhiwen , Jiang Shengwei , Zhang Linxing , Yang Teng , Zhang Xu , Zhou Lin
Published: March 2024

The development of ultrathin, stable ferroelectric materials is crucial for advancing high‐density, low‐power electronic devices. Nonetheless, ultrathin ferroelectric materials are rare due to the critical size effect. Here, a novel ferroelectric material, magnesium molybdenum oxide (Mg2Mo3O8) is presented. High‐quality ultrathin Mg2Mo3O8 crystals are synthesized using chemical vapor deposition (CVD). Ultrathin Mg2Mo3O8 has a wide bandgap (≈4.4 eV) and nonlinear optical response. Mg2Mo3O8 crystals of varying thicknesses exhibit out‐of‐plane ferroelectric properties at room temperature, with ferroelectricity retained even at a 2 nm thickness. The Mg2Mo3O8 exhibits a relatively large remanent polarization ranging from 33 to 52 µC cm−2, which is tunable by changing its thickness. Notably, Mg2Mo3O8 possesses a high Curie temperature (>980 °C) across various thicknesses. Moreover, the as‐grown Mg2Mo3O8 crystals display remarkable stability under harsh environments. This work introduces nolanites‐type crystal into ultrathin ferroelectrics. The scalable synthesis of stable ultrathin ferroelectric Mg2Mo3O8 expands the scope of ferroelectric materials and may prosper applications of ferroelectrics.
Electrochemical Hydroxylation of α‐Bromoacetophenones: Access to α‐Hydroxyacetophenones
Authors: Singh Saurabh , Ray Subhasish , Shukla Gaurav , Singh Malkeet , Singh Maya Shankar
Published: March 2024

Herein, a new method has been developed for the synthesis of various α‐hydroxyacetophenones via an electro‐oxidation process. It involves electrocatalytic hydroxylation via debromination of C(sp3)−Br bond. Here, simultaneous breaking of carbon‐bromine (C−Br) bond and formation of a new carbon‐oxygen (C−O) bond has been achieved through electrolysis of H2O using binary mixture of water and DMSO. The protocol features easy performance, oxidant and base‐free mild conditions and short reaction time.
Solvated Electrons: Dynamic Reductant in Visible Light Photoredox Catalysis
Authors: Singh Puja , Lal Nand , Shaikh Aslam C.
Published: March 2024

Open shell species are alluring significant attention owing to their unique physiochemical properties in redox chemistry for activating remarkably stable bonds. Solvated electrons are one of them that have been extensively investigated due to their high reduction potential (Ered=−2.9 V vs SHE in CH3CN), diverse substrate activation, and promising applications. If the activating species have a larger redox potential with a longer lifetime, then the broader range of substrates will be activated. Hence, the solvated electron qualifies as a super‐reductant with these qualities. However, due to safety issues, generating solvated electrons by dissolving alkali metals in an ammoniated solvent limits its use towards complicated organic transformations. Instead photochemically generated solvated electron overcome this limitation and is identified as a user‐friendly, sustainable, and much safer alternative approach for producing solvated electrons. In this minireview, we have comprehensively highlighted the recent key methods to generate the solvated electron photochemically, characterization techniques, and its application in organic transformations with selected examples. The minireview provides new opportunities for chemists to understand the conceptual, physical, and mechanistic chemistry principle of this super reductant for exploiting a new photochemical route for the transformations that are difficult to achieve by other means.
Matrix Resistance Toward Proteolytic Cleavage Controls Contractility‐Dependent Migration Modes During Angiogenic Sprouting
Authors: Weiß Martin S. , Trapani Giuseppe , Long Hongyan , Trappmann Britta
Published: March 2024

Tissue homeostasis and disease states rely on the formation of new blood vessels through angiogenic sprouting, which is tightly regulated by the properties of the surrounding extracellular matrix. While physical cues, such as matrix stiffness or degradability, have evolved as major regulators of cell function in tissue microenvironments, it remains unknown whether and how physical cues regulate endothelial cell migration during angiogenesis. To investigate this, a biomimetic model of angiogenic sprouting inside a tunable synthetic hydrogel is created. It is shown that endothelial cells sense the resistance of the surrounding matrix toward proteolytic cleavage and respond by adjusting their migration phenotype. The resistance cells encounter is impacted by the number of covalent matrix crosslinks, crosslink degradability, and the proteolytic activity of cells. When matrix resistance is high, cells switch from a collective to an actomyosin contractility‐dependent single cellular migration mode. This switch in collectivity is accompanied by a major reorganization of the actin cytoskeleton, where stress fibers are no longer visible, and F‐actin aggregates in large punctate clusters. Matrix resistance is identified as a previously unknown regulator of angiogenic sprouting and, thus, provides a mechanism by which the physical properties of the matrix impact cell migration modes through cytoskeletal remodeling.
Biomimetic Nano‐Degrader Based CD47‐SIRPα Immune Checkpoint Inhibition Promotes Macrophage Efferocytosis for Cardiac Repair
Authors: Gao Jinfeng , Pang Zhiqing , Wang Qiaozi , Tan Yiwen , Li Qiyu , Tan Haipeng , Chen Jing , Yakufu Wusiman , Wang Zhengmin , Yang Hongbo , Zhang Jinyan , Sun Dili , Weng Xueyi , Wang Qibing , Qian Juying , Song Yanan , Huang Zheyong , Ge Junbo
Published: March 2024

CD47‐SIRPα axis is an immunotherapeutic target in tumor therapy. However, current monoclonal antibody targeting CD47‐SIRPα axis is associated with on‐target off‐tumor and antigen sink effects, which significantly limit its potential clinical application. Herein, a biomimetic nano‐degrader is developed to inhibit CD47‐SIRPα axis in a site‐specific manner through SIRPα degradation, and its efficacy in acute myocardial infarction (AMI) is evaluated. The nano‐degrader is constructed by hybridizing liposome with red blood cell (RBC) membrane (RLP), which mimics the CD47 density of senescent RBCs and possesses a natural high‐affinity binding capability to SIRPα on macrophages without signaling capacity. RLP would bind with SIRPα and induce its lysosomal degradation through receptor‐mediated endocytosis. To enhance its tissue specificity, Ly6G antibody conjugation (aRLP) is applied, enabling its attachment to neutrophils and accumulation within inflammatory sites. In the myocardial infarction model, aRLP accumulated in the infarcted myocardium blocks CD47‐SIRPα axis and subsequently promoted the efferocytosis of apoptotic cardiomyocytes by macrophage, improved heart repair. This nano‐degrader efficiently degraded SIRPα in lysosomes, providing a new strategy for immunotherapy with great clinical transformation potential.
Biogenerated Oxygen‐Related Environmental Stressed Apoptotic Vesicle Targets Endothelial Cells
Authors: Zhao Qiuyu , Lu Bolun , Qian Shutong , Mao Jiayi , Zhang Liucheng , Zhang Yuguang , Mao Xiyuan , Cui Wenguo , Sun Xiaoming
Published: March 2024

The dynamic balance between hypoxia and oxidative stress constitutes the oxygen‐related microenvironment in injured tissues. Due to variability, oxygen homeostasis is usually not a therapeutic target for injured tissues. It is found that when administered intravenously, mesenchymal stem cells (MSCs) and in vitro induced apoptotic vesicles (ApoVs) exhibit similar apoptotic markers in the wound microenvironment where hypoxia and oxidative stress co‐existed, but MSCs exhibited better effects in promoting angiogenesis and wound healing. The derivation pathway of ApoVs by inducing hypoxia or oxidative stress in MSCs to simulate oxygen homeostasis in injured tissues is improved. Two types of oxygen‐related environmental stressed ApoVs are identified that directly target endothelial cells (ECs) for the accurate regulation of vascularization. Compared to normoxic and hypoxic ones, oxidatively stressed ApoVs (Oxi‐ApoVs) showed the strongest tube formation capacity. Different oxygen‐stressed ApoVs deliver similar miRNAs, which leads to the broad upregulation of EC phosphokinase activity. Finally, local delivery of Oxi‐ApoVs‐loaded hydrogel microspheres promotes wound healing. Oxi‐ApoV‐loaded microspheres achieve controlled ApoV release, targeting ECs by reducing the consumption of inflammatory cells and adapting to the proliferative phase of wound healing. Thus, the biogenerated apoptotic vesicles responding to oxygen‐related environmental stress can target ECs to promote vascularization.
Carbonized Cellulose Aerogel Derived from Waste Pomelo Peel for Rapid Hemostasis of Trauma‐Induced Bleeding
Authors: Wan Wenbing , Feng Yang , Tan Jiang , Zeng Huiping , Jalaludeen Rafeek Khan , Zeng Xiaoxi , Zheng Bin , Song Jingchun , Zhang Xiyue , Chen Shixuan , Pan Jingye
Published: March 2024

Uncontrollable massive bleeding caused by trauma will cause the patient to lose a large amount of blood and drop body temperature quickly, resulting in hemorrhagic shock. This study aims to develop a hemostatic product for hemorrhage management. In this study, waste pomelo peel as raw material is chosen. It underwent processes of carbonization, purification, and freeze‐drying. The obtained carbonized pomelo peel (CPP) is hydrophilic and exhibits a porous structure (nearly 80% porosity). The water/blood absorption ratio is significantly faster than the commercial Gelfoam and has a similar water/blood absorption capacity. In addition, the CPP showed a water‐triggered shape‐recoverable ability. Moreover, the CPP shows ideal cytocompatibility and blood compatibility in vitro and favorable tissue compatibility after long terms of subcutaneous implantation. Furthermore, CPP can absorb red blood cells and fibrin. It also can absorb platelets and activate platelets, and it is capable of achieving rapid hemostasis on the rat tail amputation and hepatectomized hemorrhage model. In addition, the CPP not only can quickly stop bleeding in the rat liver‐perforation and rabbit heart uncontrolled hemorrhage models, but also promotes rat liver and rabbit heart tissue regeneration in situ. These results suggest the CPP has shown great potential for managing uncontrolled hemorrhage.
An Antibody‐Drug Conjugate for Multiple Myeloma Prepared by Multi‐Arm Linkers
Authors: Yu Yueh‐Hsiang , Tian Wei‐Ting , Grauffel Cédric , Lin Wei‐Chen , Hsieh Ming‐Yu , Wu Pei‐Wen , Lee Hui‐Ju , Peng Chi‐Jiun , Lin Pei‐Hsuan , Chu Hsing‐Mao , Lim Carmay , Chang Tse Wen
Published: March 2024

First‐line treatment of multiple myeloma, a prevalent blood cancer lacking a cure, using anti‐CD38 daratumumab antibody and lenalidomide is often inadequate due to relapse and severe side effects. To enhance drug safety and efficacy, an antibody‐drug conjugate, TE‐1146, comprising six lenalidomide drug molecules site‐specifically conjugated to a reconfigured daratumumab to deliver cytotoxic lenalidomide to tumor cells is developed. TE‐1146 is prepared using the HighDAR platform, which employs i) a maleimide‐containing “multi‐arm linker” to conjugate multiple drug molecules creating a drug bundle, and ii) a designed peptide with a Zn2+‐binding cysteine at the C‐termini of a reconfigured daratumumab for site‐specific drug bundle conjugation. It is shown that TE‐1146 remains intact and effectively enters CD38‐expressing tumor cells, releasing lenalidomide, leading to enhanced cell‐killing effects compared to lenalidomide/daratumumab alone or their combination. This reveals the remarkable potency of lenalidomide once internalized by myeloma cells. TE‐1146 precisely delivers lenalidomide to target CD38‐overexpressing tumor cells. In contrast, lenalidomide without daratumumab cannot easily enter cells, whereas daratumumab without lenalidomide relies on Fc‐dependent effector functions to kill tumor cells.