Biomechanics and mechanobiology of the bone matrix

The bone matrix plays an indispensable role in the human body,and its unique biomechanical and mechanobiological properties have received much attention.The bone matrix has unique mechanical anisotropy and exhibits both strong toughness and high strength.These mechanical properties are closely associated with human life activities and correspond to the function of bone in the human body.None of the mechanical properties exhibited by the bone matrix is independent of its composition and structure.Studies on the biomechanics of the bone matrix can provide a reference for the preparation of more applicable bone substitute implants,bone biomimetic materials and scaffolds for bone tissue repair in humans,as well as for biomimetic applications in other fields.In providing mechanical support to the human body,bone is constantly exposed to mechanical stimuli.Through the study of the mechanobiology of the bone matrix,the response mechanism of the bone matrix to its surrounding mechanical environment can be elucidated and used for the health maintenance of bone tissue and defect regeneration.This paper summarizes the biomechanical properties of the bone matrix and their biological significance,discusses the compositional and structural basis by which the bone matrix is capable of exhibiting these mechanical properties,and studies the effects of mechanical stimuli,especially fluid shear stress,on the components of the bone matrix,cells and their interactions.The problems that occur with regard to the biomechanics and mechanobiology of the bone matrix and the corresponding challenges that may need to be faced in the future are also described.

Spatio-spectral dynamics of soliton pulsation with breathing behavior in the anomalous dispersion fiber laser

We have numerically and experimentally observed the soliton pulsation with obvious breathing behavior in the anomalous fiber laser mode-locked by a nonlinear polarization rotation technique.The numerical study of the soliton pulsation with breathing behavior was analyzed through the split-step Fourier method at first,and it was found that the phase difference caused by the polarization controller would affect the breathing characteristics.Then,taking advantage of the dispersive Fourier transform technique,we confirmed the breathing characteristic of soliton pulsation in the same fiber laser as the simulation model experimentally.These results complement the research on the breathing characteristic of soliton pulsation.

Retroperitoneal hyaline-vascular variant Castleman Disease in a patient with iron-deficiency anemia and sinus bradycardia:a case report

Objective Castleman disease, also known as giant lymph node hyperplasia, involves lesions in the lymph nodes usually located in the chest_ENREF_1, particularly in the mediastinum. Meanwhile, sinus bradycardia is a sinus rhythm slower than 60 beats per min, and it can occur in both healthy and sick individuals. However, the comorbidity of these two disorders has not been previously reported. In this paper, we report a case of a 46-year-old woman who presented with persistent sinus bradycardia and irondeficiency anemia. Diagnostic work-up revealed hepatosplenomegaly and a giant mass near the splenic hilum. The mass was removed surgically; after which, the patient's bradycardia resolved immediately, while her anemia was corrected after subsequent chemotherapy. Pathological examination revealed lymph nodes with benign lesions, and the patient was diagnosed with hyaline-vascular variant of Castleman disease. This is the first documented case of sinus bradycardia associated with Castleman disease. In this paper, we describe the case characteristics, discuss the possible pathogenesis, and consider the appropriate treatment of symptomatic sinus bradycardia accompanying Castleman disease.

Two-Dimensional Tellurium:Progress,Challenges,and Prospects

Since the successful fabrication of two-dimensional(2D)tellurium(Te)in 2017,its fascinating properties including a thickness dependence bandgap,environmental stability,piezoelectric effect,high carrier mobility,and photoresponse among others show great potential for various applications.These include photodetectors,field-effect transistors,piezoelectric devices,modulators,and energy harvesting devices.However,as a new member of the 2D material family,much less known is about 2D Te compared to other 2D materials.Motivated by this lack of knowledge,we review the recent progress of research into 2D Te nanoflakes.Firstly,we introduce the background and motivation of this review.Then,the crystal structures and synthesis methods are presented,followed by an introduction to their physical properties and applications.Finally,the challenges and further development directions are summarized.We believe that milestone investigations of 2D Te nanoflakes will emerge soon,which will bring about great industrial revelations in 2D materials-based nanodevice commercialization.

A Novel Time-aware Frame Adjustment Strategy for RFID Anti-collision

Recently,object identification with radio frequency identification(RFID)technology is becoming increasingly popular.Identification time is a key performance metric to evaluate the RFID system.The present paper analyzes the deficiencies of the state-of-the-arts algorithms and proposes a novel sub-frame-based algorithm with adaptive frame breaking policy to lower the tag identification time for EPC global C1 Gen2 UHF RFID standard.Through the observation of slot statistics in a sub-frame,the reader estimates the tag quantity and efficiently calculates an optimal frame size to fit the unread tags.Only when the expected average identification time in the calculated frame size is less than that in the previous frame size,the reader starts the new frame.Moreover,the estimation of the proposed algorithm is implemented by the look-up tables,which allows dramatically reduction in the computational complexity.Simulation results show noticeable throughput and time efficiency improvements of the proposed solution over the existing approaches.

General Expressions for the Circular Constant π

From ancient times to the present, mathematicians have put forward many series expressions of the circular constant. Because of the importance of the circular constant to mathematical physics, the research on circular constant has never stopped. In this paper, the general function expression of the circular constant was given by studying the transient heat conduction equation. From the physical aspect of the derivation process of the circular constant expression, we can conclude that there is an infinite number of different series exist that can be used to express π.

A case of chronic pancreatitis treated by laparoscopic duodenum-preserving pancreatic head resection

Pancreaticoduodenectomy(PD) has long been used for chronic pancreatitis(CP), but greatly affects the postoperative quality of life. A new procedure called duodenum-preserving pancreatic head resection(DPPHR) has been introduced, and has little effect on the structure and function of the digestive system. With the development of minimally invasive surgical techniques, treatment of CP can be performed with laparoscopic DPPHR(LDPPHR). We present a case of CP that was successfully treated with LDPPHR. The postoperative pathological diagnosis was pancreatitis, demonstrating the feasibility of LDPPHR. We recommend this minimally invasive surgical method as preferred treatment for CP.

Corrigendum to“Development of methods for detecting the fate of mesenchymal stem cells regulated by bone bioactive materials”[Bioact.Mater.6(3)(2021)613-626]

The authors regret that the last name and first name of all authors are reversed in the original article.The correct writing is as follows:Le Jiang,a,b#;Zhongqun Liu,a,b#;Zhaoyan Wang,d,e,f;Yijun Su,a,b;Yingjin Wang,a,b;Yaojie Wei,a,b;Yanan Jiang,c;Zhanrong Jia,c;Chunyang Ma,a,b;Fangli Gang,a,b;Nan Xu,a,b;Lingyun Zhao,a,b;Xiumei Wang,a,b;Qiong Wu,d,e,f;Xiong Lu,c,*and Xiaodan Sun,a,b,*a.State Key Laboratory of New Ceramics and Fine Processing,School of Materials Science and Engineering,Tsinghua University,Beijing 100084,People’s Republic of China;b.Key Laboratory of Advanced Materials of Ministry of Education of China,School of Materials Science and Engineering,Tsinghua University,Beijing 100084,People’s Republic of China;c.Key Lab of Advanced Technologies of Materials of Ministry of Education,School of Materials Science and Engineering,Southwest Jiaotong University,Chengdu 610031,People’s Republic of China d.MOE Key Laboratory of Bioinformatics,Tsinghua University,Beijing,100084,People’s Republic of China e.Center for Synthetic and Systems Biology,Tsinghua University,Beijing,100084,People’s Republic of China f.School of Life Sciences,Tsinghua University,Beijing,100084,People’s Republic of China.

Pure-high-even-order dispersion bound solitons complexes in ultra-fast fiber lasers

Temporal solitons have been the focus of much research due to their fascinating physical properties.These solitons can form bound states,which are fundamentally crucial modes in fiber laser and present striking analogies with their matter molecules counterparts,which means they have potential applications in large-capacity transmission and alloptical information storage.Although traditionally,second-order dispersion has been the dominant dispersion for conventional solitons,recent experimental and theoretical research has shown that pure-high-even-order dispersion(PHEOD)solitons with energy-width scaling can arise from the interaction of arbitrary negative-even-order dispersion and Kerr nonlinearity.Despite these advancements,research on the bound states of PHEOD solitons is currently nonexistent.In this study,we obtained PHEOD bound solitons in a fiber laser using an intra-cavity spectral pulse shaper for high-order dispersion management.Specifically,we experimentally demonstrate the existence of PHEOD solitons and PHEOD bound solitons with pure-quartic,-sextic,-octic,and-decic dispersion.Numerical simulations corroborate these experimental observations.Furthermore,vibrating phase PHEOD bound soliton pairs,sliding phase PHEOD bound soliton pairs,and hybrid phase PHEOD bound tri-soliton are discovered and characterized.These results broaden the fundamental understanding of solitons and show the universality of multi-soliton patterns.

Numerical study of a bi-directional in-band pumped dysprosium-doped fluoride fiber laser at 3.2μm

Dy^(3+)-doped fluoride fiber lasers have important applications in environment monitoring,real-time sensing,and polymer processing.At present,achieving a high-efficiency and high-power Dy^(3+)-doped fluoride fiber laser in the mid-infrared(mid-IR)region over 3μm is a scientific and technological frontier.Typically,Dy^(3+)-doped fluoride fiber lasers use a unidirectional pumping method,which suffers from the drawback of high thermal loading density on the fiber tips,thus limiting power scalability.In this study,a bi-directional in-band pumping scheme,to address the limitations of output power scaling and to enhance the efficiency of the Dy^(3+)-doped fluoride fiber laser at 3.2μm,is investigated numerically based on rate equations and propagation equations.Detailed simulation results reveal that the optical‒optical efficiency of the bi-directional in-band pumped Dy^(3+)-doped fluoride fiber laser can reach 75.1%,approaching the Stokes limit of 87.3%.The potential for further improvement of the efficiency of the Dy^(3+)-doped fluoride fiber laser is also discussed.The bi-directional pumping scheme offers the intrinsic advantage of mitigating the thermal load on the fiber tips,unlike unidirectional pumping,in addition to its high efficiency.As a result,it is expected to significantly scale the power output of Dy^(3+)-doped fluoride fiber lasers in the mid-IR regime.

Short-pulsed Raman fiber laser and its dynamics

We provide a perspective review over the recent development of short-pulsed Raman fiber lasers(RFLs),which can provide laser emissions with flexible wavelengths for a variety of applications as well as an excellent platform to investigate various nonlinear pulse dynamics behaviors that cannot be captured in conventional rare-earth(RE)doped counterparts.Various pulse generation techniques have been explored in RFLs.However,the output pulse performance in terms of the pulse energy,duration and stability from short-pulsed RFLs is still inferior to their RE-doped counterparts despite significant advances made over the past few decades.Therefore,more efforts are required to improve these targets.In this review,we present a detailed overview of the short-pulsed RFLs based on different mechanisms from the principle to the experiment,including the Q-switching,gainswitching,mode-locking,synchronous pumping and other innovative techniques.In addition,Raman-induced pulse dynamics in ultrafast RFLs and RE-doped mode-locked fiber lasers(MLFLs)are briefly reviewed.Finally,a perspective outlook for the future ultrafast RFLs is provided based on their potential applications in industrial and scientific research areas.

Ultrabroadband,few-cycle pulses directly from a Mamyshev fiber oscillator

While the performance of mode-locked fiber lasers has been improved significantly,the limited gain bandwidth restricts them from generating ultrashort pulses approaching a few cycles or even shorter.Here we present a novel method to achieve few-cycle pulses(~5 cycles)with an ultrabroad spectrum(~400 nm at-20 dB)from a Mamyshev oscillator configuration by inserting a highly nonlinear photonic crystal fiber and a dispersion delay line into the cavity.A dramatic intracavity spectral broadening can be stabilized by the unique nonlinear processes of a self-similar evolution as a nonlinear attractor in the gain fiber and a"perfect"saturable absorber action of the Mamyshev oscillator.To the best of our knowledge,this is the shortest pulse width and broadest spectrum directly generated from a fiber laser.

Composite double-layer microneedle loaded with traditional Chinese medicine for the treatment of androgenic alopecia

Androgenetic alopecia(AGA)is an androgen-mediated alopecia affected by both genes and hormones.Medication is a relatively common treatment.As a new drug delivery method,microneedles(MNs)can effectively break through the stratum corneum barrier,deliver drugs more efficiently,and achieve better therapeutic effects.In this study,we develop a composite double-layer MN through multi-step casting fabrication using a polydimethylsiloxane mold.The needle tip was fabricated by mixed solution of chitosan and polyvinylpyrrolidone which was loaded with Polygonum multiflorum extract,and the base layer was prepared by mixed solution of polyvinyl alcohol and polyvinylpyrrolidone.In vitro mechanical tests showed that the maximum load of a single tip of the drug-loaded MN was about 3.5 N,which met the mechanical requirements of skin puncture(>1 N).The drug release experiment showed that the MN could achieve gradual drug release.In the animal experiment,pigmentation and hair regrowth occurred earlier in the Polygonum multiflorum-MN(Pm-MN)group than in the other groups,and hair growth finally appeared in almost the entire area.Compared with the AGA model mice,mice in the Pm-MN group achieved an increase in the number and diameter of hair follicles.In conclusion,the Pm-MN is scientific and feasible for treating AGA.

Two-dimensional tin diselenide nanosheets pretreated with an alkaloid for near-and mid-infrared ultrafast photonics

Two-dimensional(2D)tin diselenide(SnSe2),a novel layered material with excellent optical and electronic properties,has been extensively investigated in various promising applications,including photodetectors,optical switching,and ultrafast photonics.In this work,SnSe2 nanosheets have been obtained after pretreatment in an alkaloid,exhibiting high optical absorption and electron-enriched properties.Besides,the performances of the prepared SnSe2 in near-infrared(NIR)and mid-infrared(MIR)ultrafast photonics are presented.Notably,by employing the SnSe2-deposited microfiber device as a saturable absorber(SA)exhibiting typical nonlinear optical absorption properties,stable ultrashort pulses and rogue waves are realized in an erbium-doped fiber laser.Furthermore,the SnSe2-deposited SA device is also applied to a thulium-doped fiber laser to achieve stable ultrashort pulses.This study indicates that SnSe2 is expected to be a suitable candidate for ultrafast fiber lasers in the NIR and MIR regions.