BACKGROUND Childhood obesity has emerged in the last decades as an important public health problem worldwide.Although relationships between obesity and flatfoot have been shown,no studies have investigated the influen...BACKGROUND Childhood obesity has emerged in the last decades as an important public health problem worldwide.Although relationships between obesity and flatfoot have been shown,no studies have investigated the influence of obesity on arthroereisis outcomes.AIM To evaluate correlations between childhood overweight/obesity and clinical and radiographic outcomes after subtalar arthroereisis with self-locking implants.METHODS This retrospective study included one hundred and sixty-nine pediatric patients(10-14 years old)who underwent subtalar arthroereisis(PEEK PitStop®device)for severe flexible flatfoot.Exclusion criteria were additional procedures,revision of previous corrective surgeries,rigid flatfoot with severe deformity,and neurologi-cal or post-traumatic flatfoot.Preoperative/postoperative European Foot and Ankle Society(EFAS)and visual analogue scale(VAS)scores were determined;radiographic assessment was conducted on weight-bearing foot X-rays:Kite angle,first metatarsal-talus angle,Meary angle,calcaneal pitch angle and lateral talo-calcaneal angle were analyzed.RESULTS EFAS and VAS scores improved post-operatively in the whole population.Only seven cases with complications were reported.Radiographic assessment revealed an improvement in all angles.Statistical analysis demonstrated that the impact of obesity was significant on arthroereisis outcomes:Relationships were reported between BMI and postoperative EFAS/VAS scores,postoperative calcaneal pitch angle,Kite angle,Meary angle and talo-first meta-tarsal angle.CONCLUSION Although arthroereisis represents a very effective and valid treatment for flatfoot both in normal weight and obese children,obesity significantly influences clinical and radiographic outcomes of arthroereisis,and obese children tend to perceive more pain and discomfort.展开更多
The adoption of Internet of Things(IoT)sensing devices is growing rapidly due to their ability to provide realtime services.However,it is constrained by limited data storage and processing power.It offloads its massiv...The adoption of Internet of Things(IoT)sensing devices is growing rapidly due to their ability to provide realtime services.However,it is constrained by limited data storage and processing power.It offloads its massive data stream to edge devices and the cloud for adequate storage and processing.This further leads to the challenges of data outliers,data redundancies,and cloud resource load balancing that would affect the execution and outcome of data streams.This paper presents a review of existing analytics algorithms deployed on IoT-enabled edge cloud infrastructure that resolved the challenges of data outliers,data redundancies,and cloud resource load balancing.The review highlights the problems solved,the results,the weaknesses of the existing algorithms,and the physical and virtual cloud storage servers for resource load balancing.In addition,it discusses the adoption of network protocols that govern the interaction between the three-layer architecture of IoT sensing devices enabled edge cloud and its prevailing challenges.A total of 72 algorithms covering the categories of classification,regression,clustering,deep learning,and optimization have been reviewed.The classification approach has been widely adopted to solve the problem of redundant data,while clustering and optimization approaches are more used for outlier detection and cloud resource allocation.展开更多
We demonstrate the generation of Q-switched pulses from an ytterbium-doped fiber laser(YDFL) using quantum dot(QD) CdSe as a passive saturable absorber(SA). The CdSe QD is fabricated by the synthesis of CdO,Se, ...We demonstrate the generation of Q-switched pulses from an ytterbium-doped fiber laser(YDFL) using quantum dot(QD) CdSe as a passive saturable absorber(SA). The CdSe QD is fabricated by the synthesis of CdO,Se, and manganese acetate and paraffin oil and oleic acid as the solvent and surfactant, respectively. The CdSe QD is then doped into poly-methyl-methacrylate(PMMA) via an emulsion polymerization process. A PMMAhosted CdSe QD thin flake with a homogeneous end surface is then formed and placed between two ferrules and assembled in a YDFL cavity to achieve the Q-switching operation with a repetition rate of 24.45 to 40.50 kHz while varying the pump power from 975 to 1196 mW. The pulse width changes from 6.78 to 3.65 μs with a maximum calculated pulse energy at 0.77 μJ at a pump power of 1101 mW. This work may be the first demonstration of CdSe QD-based Q-switching in an all-fiber configuration that should give proportional insight into semiconductor QD materials in photonics applications.展开更多
Energy consumption of sensor nodes is one of the crucial issues in prolonging the lifetime of wireless sensor networks. One of the methods that can improve the utilization of sensor nodes batteries is the clustering m...Energy consumption of sensor nodes is one of the crucial issues in prolonging the lifetime of wireless sensor networks. One of the methods that can improve the utilization of sensor nodes batteries is the clustering method. In this paper, we propose a green clustering protocol for mobile sensor networks using particle swarm optimization (PSO) algorithm. We define a new fitness function that can optimize the energy consumption of the whole network and minimize the relative distance between cluster heads and their respective member nodes. We also take into account the mobility factor when defining the cluster membership, so that the sensor nodes can join the cluster that has the similar mobility pattern. The performance of the proposed protocol is compared with well-known clustering protocols developed for wireless sensor networks such as LEACH (low-energy adaptive clustering hierarchy) and protocols designed for sensor networks with mobile nodes called CM-IR (clustering mobility-invalid round). In addition, we also modify the improved version of LEACH called MLEACH-C, so that it is applicable to the mobile sensor nodes environment. Simulation results demonstrate that the proposed protocol using PSO algorithm can improve the energy consumption of the network, achieve better network lifetime, and increase the data delivered at the base station.展开更多
Atherosclerosis is the precedent to ischemic heart disease, which may lead to angina, myocardial infarct, or heart failure;or to ischemic cerebrovascular disease, which may lead to stroke. The prevailing belief underl...Atherosclerosis is the precedent to ischemic heart disease, which may lead to angina, myocardial infarct, or heart failure;or to ischemic cerebrovascular disease, which may lead to stroke. The prevailing belief underlying conventional approaches to treatment of atherosclerosis and its sequel is that a diet high in cholesterol and saturated fat is the main contributory factor, triggering cholesterol build up in the intima of the blood vessels. Over the last 60 years, the blame has shifted from fats, to saturated fats, to low-density lipoprotein (LDL), and finally to oxidized LDL (Ox-LDL). Therapy has been predominantly aimed at lowering cholesterol and control of risk factors. However, there is an alternative hypothesis about the cause of heart disease linking it to the weakening of the vascular collagen matrix at the sites of high hemodynamic stress (coronary arteries) which triggers the infiltration of lipoprotein(apo) [Lp(a)] and plaque development. Accordingly, the vascular deposition of large molecules such as Lp(a) and atherosclerosis is the result of the body’s endogenous protective mechanism to reinforce the weakened artery walls. Understanding this mechanism may guide the natural prevention of this disease and form the basis for developing effective therapeutic strategies aiming at natural reversal of atherosclerosis through the reinforcement of the vascular wall structure as its primary goal. This reappraisal of atherosclerosis and the cholesterol theory looked at the historical development of the theory, and the Rath and Pauling unified theory of cardiovascular disease.展开更多
We demonstrate the generation of a Q-switching pulse train in an erbium-doped fiber laser (EDFL) cavity using a newly developed cadmium selenide (CdSe) based saturable absorber (SA). The SA is obtained by embedd...We demonstrate the generation of a Q-switching pulse train in an erbium-doped fiber laser (EDFL) cavity using a newly developed cadmium selenide (CdSe) based saturable absorber (SA). The SA is obtained by embedding CdSe nanomaterials into a polymethyl methacrylate (PMMA) microfiber. It is incorporated into an EDFL cavity to generate a Q-switched laser operating at 1533.6nm. The repetition rates of the produced pulse train are tunable within 37–64kHz as the pump power is varied from 34mW to 74mW. The corresponding pulse width reduces from 7.96μs to 4.84μs, and the maximum pulse energy of 1.16nJ is obtained at the pump power of 74mW.展开更多
A stable Q-switched erbium doped fiber laser emitting at 1558 nm is demonstrated using a cadmium selenide(CdSe) material coated onto a side-polished D-shape fiber as the saturable absorber(SA). By elevating the in...A stable Q-switched erbium doped fiber laser emitting at 1558 nm is demonstrated using a cadmium selenide(CdSe) material coated onto a side-polished D-shape fiber as the saturable absorber(SA). By elevating the input pump power from the threshold of 91 mW to the maximum available power of 136 mW, a pulse train with a maximum repetition rate of 57.44 kHz, minimum pulse width of 3.76 us, maximum average output power of7.99 mW, maximum pulse energy of 0.1391 uJ, and maximum peak power of 36.99 mW are obtained. The signalto-noise ratio of the spectrum is measured to be around 75 dB. This CdSe based SA is simple, robust, and reliable,and thus suitable for making a portable pulse laser source.展开更多
A mode-locked erbium doped fiber laser(EDFL) is demonstrated using the vanadium oxide(V2O5) material as a saturable absorber(SA). The V2O5 based SA is hosted into poly ethylene oxide film and attached on fiber f...A mode-locked erbium doped fiber laser(EDFL) is demonstrated using the vanadium oxide(V2O5) material as a saturable absorber(SA). The V2O5 based SA is hosted into poly ethylene oxide film and attached on fiber ferule in the laser cavity. It shows 7% modulation depth with 71 MW/cm2 saturation intensity. By incorporating the SA inside the EDFL cavity with managed intra-cavity dispersion, ultrashort soliton pulses are successfully generated with a full width at half maximum of 3.14 ps. The laser operated at central wavelength of 1559.25 nm and repetition frequency of 1 MHz.展开更多
We demonstrate a femtosecond mode-locked erbium-doped fiber laser(EDFL) using a nickel oxide(Ni O) as a saturable absorber(SA). Ni O nanoparticles are hosted into polyethylene oxide film and attached to fiber fe...We demonstrate a femtosecond mode-locked erbium-doped fiber laser(EDFL) using a nickel oxide(Ni O) as a saturable absorber(SA). Ni O nanoparticles are hosted into polyethylene oxide film and attached to fiber ferrule in the laser cavity. The Ni O-SA shows a 39% modulation depth with a 0.04 MW∕cm^2 saturation intensity. Our ring laser cavity based on erbium-doped active fiber with managed intracavity dispersion has the ability to generate ultrashort pulses with a full width at half-maximum(FWHM) of around 2.85 nm centered at 1561.8 nm.The pulses repeat at a frequency of 0.96 MHz and duration of 950 fs.展开更多
We demonstrate an ultrafast fiber laser based on transition metal dichalcogenide materials which are tungsten disulfide (WS<sub>2</sub>) and molybdenum disulfide (MoS<sub>2</sub>) as saturable ...We demonstrate an ultrafast fiber laser based on transition metal dichalcogenide materials which are tungsten disulfide (WS<sub>2</sub>) and molybdenum disulfide (MoS<sub>2</sub>) as saturable absorber (SA). These materials are fabricated via a simple drop-casting method. By employing WS<sub>2</sub>, we obtain a stable harmonic mode-locking at the threshold pump power of 184 mW, and the generated soliton pulse has 3.48 MHz of repetition rate. At the maximum pump power of 250 mW, we also obtain a small value of pulse duration, 2.43 ps with signal-to-noise ratio (SNR) of 57 dB. For MoS<sub>2</sub> SA, the pulse is generated at 105 mW pump power with repetition rate of 1.16 MHz. However, the pulse duration cannot be detected by the autocorrelator device as the pulse duration recorded is 468 ns, with the SNR value of 35 dB.展开更多
BACKGROUND Primary synovial chondromatosis(PSC) is a rare arthropathy of the synovial joints characterized by the formation of cartilaginous nodules, which may detach and become loose bodies within the joint and may u...BACKGROUND Primary synovial chondromatosis(PSC) is a rare arthropathy of the synovial joints characterized by the formation of cartilaginous nodules, which may detach and become loose bodies within the joint and may undergo secondary proliferation. PSC of the foot and ankle is exceedingly rare, with only a few cases reported in the literature. The diagnosis may be difficult and delayed until operative treatment, when it is confirmed by histological assessment. PSC may degenerate into chondrosarcoma. Operative treatment is the gold standard aiming to minimize pain, improve function, prevent or limit progression of arthritis. Surgical treatment consists in debridement by arthrotomic or arthroscopic management, but there is no consensus in the literature about timing of surgery and surgical technique. Thus, the aim of this study is to report the outcomes of the surgical treatment of two cases, together with a literature review.CASE SUMMARY We report two cases of patients affected by PSC of the foot in stage III, according to the Milgram classification: the former PSC localized in the ankle that underwent open surgery consisted of loose bodies removal;the latter in the subtalar joint, and the choice of treatment was the arthrotomy and debridement from loose bodies, in addition to the subtalar arthrodesis. Both patients returned to complete daily and working life after surgery.CONCLUSION Synovial chondromatosis is a rare benign pathology, even rarer in the ankle joint and especially in the foot. Surgery should be minimal in patients with ankle PSC,choosing the correct timing, waiting if possible until stage III. More aggressive and early surgery should be performed in patients with PSC of the foot,particularly the subtalar joint, due to the high risk of arthritic evolution.展开更多
We demonstrate a Q-switched Raman fiber laser using molybdenum disulfide (MoS2) as a saturable absorber (SA). The SA is assembled by depositing a mechanically exfoliated MoS2 onto a fiber ferrule facet before it i...We demonstrate a Q-switched Raman fiber laser using molybdenum disulfide (MoS2) as a saturable absorber (SA). The SA is assembled by depositing a mechanically exfoliated MoS2 onto a fiber ferrule facet before it is matched with another clean ferrule via a connector. It is inserted in a Raman fiber laser cavity with a total cavity length of about 8kin to generate a Q-switching pulse train operating at 1560.2nm. A 7.7-kin-long dispersion compensating fiber with 584 ps.nm-i km-1 of dispersion is used as a nonlinear gain medium. As the pump power is increased from 395 m W to 422 m W, the repetition rate of the Q-switching pulses can be increased from 132.7 to 137.4 kHz while the pulse width is concurrently decreased from 3.35μs to 3.03μs. The maximum pulse energy of 54.3 nJ is obtained at the maximum pump power of 422 roW. These results show that the mechanically exfoliated MoS2 SA has a great potential to be used for pulse generation in Raman fiber laser systems.展开更多
Dear Sir,Triamcinolone acetonide(TA)is worldwide available therapeutic agent that is commonly used throughout medicine.TA remains a safe and important ophthalmic therapeutic agent even after the advent of angiogenes...Dear Sir,Triamcinolone acetonide(TA)is worldwide available therapeutic agent that is commonly used throughout medicine.TA remains a safe and important ophthalmic therapeutic agent even after the advent of angiogenesis inhibitors[1-2].展开更多
We demonstrate a Q-switched ytterbium-doped fiber laser (YDFL) using a newly developed multi-layer black phosphorous (BP) saturable absorber (SA). The BP SA is prepared by mechanically exfoliating a BP crystal a...We demonstrate a Q-switched ytterbium-doped fiber laser (YDFL) using a newly developed multi-layer black phosphorous (BP) saturable absorber (SA). The BP SA is prepared by mechanically exfoliating a BP crystal and sticking the acquired BP flakes onto a scotch tape. A small piece of the tape is then placed between two ferrules and incorporated in a YDFL cavity to achieve a stable Q-switched operation in a 1.0 μm region. The laser has a pump threshold of 55.1 mW, a pulse repetition rate that is tunable from 8.2 to 32.9 kHz, and the narrowest pulse width of 10.8 μs. The highest pulse energy of 328 nJ is achieved at the pump power of 97.6 mW. Our results show that multi-layer BP is a promising SA for Q-switching laser operation.展开更多
This paper presents a collaborative beamforming (CB) technique to organize the sensor node's location in a linear array for green wireless sensor network (WSN) applications. In this method, only selected clusters...This paper presents a collaborative beamforming (CB) technique to organize the sensor node's location in a linear array for green wireless sensor network (WSN) applications. In this method, only selected clusters and active CB nodes are needed each time to perform CB in WSNs. The proposed least-square linear array (LSLA) manages to select nodes to perform as a linear antenna array (LAA), which is similar to and as outstanding as the conventional uniform linear array (ULA). The LSLA technique is also able to solve positioning error problems that exist in the random nodes deployment. The beampattern fluctuations have been analyzed due to the random positions of sensor nodes. Performances in terms of normalized power gains are given. It is demonstrated by a simulation that the proposed technique gives similar performances to the conventional ULA and at the same time exhibits lower complexity.展开更多
Cloud internet of things(IoT)is an emerging technology that is already impelling the daily activities of our lives.However,the enormous resources(data and physical features of things)generated from Cloud-enabled IoT s...Cloud internet of things(IoT)is an emerging technology that is already impelling the daily activities of our lives.However,the enormous resources(data and physical features of things)generated from Cloud-enabled IoT sensing devices are lacking suitable managerial approaches.Existing research surveys on Cloud IoT mainly focused on its fundamentals,definitions and layered architecture as well as security challenges.Going by the current literature,none of the existing researches is yet to provide a detailed analysis on the approaches deployed to manage the heterogeneous and dynamic resource data generated by sensor devices in the cloud-enabled IoT paradigm.Hence,to bridge this gap,the existing algorithms designed to manage resource data on various CloudloT application domains are investigated and analyzed.The emergence of CloudloT,followed by previous related survey articles in this field,which motivated the current study is presented.Furthermore,the utilization of simulation environment,highlighting the programming languages and a brief description of the simulation pack-ages adopted to design and evaluate the performance of the algorithms are examined.The utilization of diverse network communication protocols and gateways to aid resource dissemina-tion in the cloud-enabled IoT network infrastructure are also discussed.The future work as discussed in previous researches,which pave the way for future research directions in this field is also presented,and ends with concluding remarks.展开更多
We demonstrate the generation of mode-locked pulses in an erbium-doped fiber laser(EDFL) by using a new manganese-doped cadmium selenide quantum-dots-based saturable absorber. The laser produces a soliton pulse trai...We demonstrate the generation of mode-locked pulses in an erbium-doped fiber laser(EDFL) by using a new manganese-doped cadmium selenide quantum-dots-based saturable absorber. The laser produces a soliton pulse train operating at 1561.1 nm with a repetition rate of 1 MHz, as the pump power is varied from 113 to 250 m W.At the maximum pump power, we obtain the pulse duration of 459 ns with a signal-to-noise ratio of 50 dB.展开更多
A retrospective analysis was performed of patients who received a paracentesis immediately following an intravitreal injection of bevacizumab or triamcinolone acetonide.These patients were previously diagnosed as havi...A retrospective analysis was performed of patients who received a paracentesis immediately following an intravitreal injection of bevacizumab or triamcinolone acetonide.These patients were previously diagnosed as having glaucoma,ocular hypertension,or had responded previously with sustained elevated intraocular pressure.Of 1661 procedures were performed.Totally 219(13%) of the injections were on phakic patients.A median(SD) of 210 μL(40 μL) of aqueous was removed during each paracentesis.There were no reported incidences of any complications.We propose performing a paracentesis immediately following intravitreal injections for patients at risk for ocular hypertension,glaucoma,and retinal vein or artery occlusion.展开更多
We demonstrate a Q-switched erbium-doped fiber laser (EDFL) using a newly developed zinc oxide- (ZnO) based saturable absorber (SA). The SA is fabricated by embedding a prepared ZnO powder into a poly(vinyl alc...We demonstrate a Q-switched erbium-doped fiber laser (EDFL) using a newly developed zinc oxide- (ZnO) based saturable absorber (SA). The SA is fabricated by embedding a prepared ZnO powder into a poly(vinyl alcohol) film. A small piece of the film is then sandwiched between two fiber ferrules and is incorporated in an EDFL cavity for generating a stable Q-switching pulse train. The EDFL operates at 1560.4nm with a pump power threshold of 11.8mW, a pulse repetition rate tunable from 22.79 to 61.43kHz, and the smallest pulse width of 7.00 μs. The Q-switching pulse shows no spectral modulation with a peak-to-pedestal ratio of 62 dB indicating the high stability of the laser. These results show that the ZnO powder has a great potential to be used for pulsed laser applications.展开更多
文摘BACKGROUND Childhood obesity has emerged in the last decades as an important public health problem worldwide.Although relationships between obesity and flatfoot have been shown,no studies have investigated the influence of obesity on arthroereisis outcomes.AIM To evaluate correlations between childhood overweight/obesity and clinical and radiographic outcomes after subtalar arthroereisis with self-locking implants.METHODS This retrospective study included one hundred and sixty-nine pediatric patients(10-14 years old)who underwent subtalar arthroereisis(PEEK PitStop®device)for severe flexible flatfoot.Exclusion criteria were additional procedures,revision of previous corrective surgeries,rigid flatfoot with severe deformity,and neurologi-cal or post-traumatic flatfoot.Preoperative/postoperative European Foot and Ankle Society(EFAS)and visual analogue scale(VAS)scores were determined;radiographic assessment was conducted on weight-bearing foot X-rays:Kite angle,first metatarsal-talus angle,Meary angle,calcaneal pitch angle and lateral talo-calcaneal angle were analyzed.RESULTS EFAS and VAS scores improved post-operatively in the whole population.Only seven cases with complications were reported.Radiographic assessment revealed an improvement in all angles.Statistical analysis demonstrated that the impact of obesity was significant on arthroereisis outcomes:Relationships were reported between BMI and postoperative EFAS/VAS scores,postoperative calcaneal pitch angle,Kite angle,Meary angle and talo-first meta-tarsal angle.CONCLUSION Although arthroereisis represents a very effective and valid treatment for flatfoot both in normal weight and obese children,obesity significantly influences clinical and radiographic outcomes of arthroereisis,and obese children tend to perceive more pain and discomfort.
文摘The adoption of Internet of Things(IoT)sensing devices is growing rapidly due to their ability to provide realtime services.However,it is constrained by limited data storage and processing power.It offloads its massive data stream to edge devices and the cloud for adequate storage and processing.This further leads to the challenges of data outliers,data redundancies,and cloud resource load balancing that would affect the execution and outcome of data streams.This paper presents a review of existing analytics algorithms deployed on IoT-enabled edge cloud infrastructure that resolved the challenges of data outliers,data redundancies,and cloud resource load balancing.The review highlights the problems solved,the results,the weaknesses of the existing algorithms,and the physical and virtual cloud storage servers for resource load balancing.In addition,it discusses the adoption of network protocols that govern the interaction between the three-layer architecture of IoT sensing devices enabled edge cloud and its prevailing challenges.A total of 72 algorithms covering the categories of classification,regression,clustering,deep learning,and optimization have been reviewed.The classification approach has been widely adopted to solve the problem of redundant data,while clustering and optimization approaches are more used for outlier detection and cloud resource allocation.
文摘We demonstrate the generation of Q-switched pulses from an ytterbium-doped fiber laser(YDFL) using quantum dot(QD) CdSe as a passive saturable absorber(SA). The CdSe QD is fabricated by the synthesis of CdO,Se, and manganese acetate and paraffin oil and oleic acid as the solvent and surfactant, respectively. The CdSe QD is then doped into poly-methyl-methacrylate(PMMA) via an emulsion polymerization process. A PMMAhosted CdSe QD thin flake with a homogeneous end surface is then formed and placed between two ferrules and assembled in a YDFL cavity to achieve the Q-switching operation with a repetition rate of 24.45 to 40.50 kHz while varying the pump power from 975 to 1196 mW. The pulse width changes from 6.78 to 3.65 μs with a maximum calculated pulse energy at 0.77 μJ at a pump power of 1101 mW. This work may be the first demonstration of CdSe QD-based Q-switching in an all-fiber configuration that should give proportional insight into semiconductor QD materials in photonics applications.
基金supported by Ministry of Higher Education(MOHE)Malaysia and the Research Management Center(RMC)of Universiti Teknologi Malaysia under Fundamental Research Grant Scheme(FRGS)Grant No.R.J130000.7823.4F641
文摘Energy consumption of sensor nodes is one of the crucial issues in prolonging the lifetime of wireless sensor networks. One of the methods that can improve the utilization of sensor nodes batteries is the clustering method. In this paper, we propose a green clustering protocol for mobile sensor networks using particle swarm optimization (PSO) algorithm. We define a new fitness function that can optimize the energy consumption of the whole network and minimize the relative distance between cluster heads and their respective member nodes. We also take into account the mobility factor when defining the cluster membership, so that the sensor nodes can join the cluster that has the similar mobility pattern. The performance of the proposed protocol is compared with well-known clustering protocols developed for wireless sensor networks such as LEACH (low-energy adaptive clustering hierarchy) and protocols designed for sensor networks with mobile nodes called CM-IR (clustering mobility-invalid round). In addition, we also modify the improved version of LEACH called MLEACH-C, so that it is applicable to the mobile sensor nodes environment. Simulation results demonstrate that the proposed protocol using PSO algorithm can improve the energy consumption of the network, achieve better network lifetime, and increase the data delivered at the base station.
文摘Atherosclerosis is the precedent to ischemic heart disease, which may lead to angina, myocardial infarct, or heart failure;or to ischemic cerebrovascular disease, which may lead to stroke. The prevailing belief underlying conventional approaches to treatment of atherosclerosis and its sequel is that a diet high in cholesterol and saturated fat is the main contributory factor, triggering cholesterol build up in the intima of the blood vessels. Over the last 60 years, the blame has shifted from fats, to saturated fats, to low-density lipoprotein (LDL), and finally to oxidized LDL (Ox-LDL). Therapy has been predominantly aimed at lowering cholesterol and control of risk factors. However, there is an alternative hypothesis about the cause of heart disease linking it to the weakening of the vascular collagen matrix at the sites of high hemodynamic stress (coronary arteries) which triggers the infiltration of lipoprotein(apo) [Lp(a)] and plaque development. Accordingly, the vascular deposition of large molecules such as Lp(a) and atherosclerosis is the result of the body’s endogenous protective mechanism to reinforce the weakened artery walls. Understanding this mechanism may guide the natural prevention of this disease and form the basis for developing effective therapeutic strategies aiming at natural reversal of atherosclerosis through the reinforcement of the vascular wall structure as its primary goal. This reappraisal of atherosclerosis and the cholesterol theory looked at the historical development of the theory, and the Rath and Pauling unified theory of cardiovascular disease.
文摘We demonstrate the generation of a Q-switching pulse train in an erbium-doped fiber laser (EDFL) cavity using a newly developed cadmium selenide (CdSe) based saturable absorber (SA). The SA is obtained by embedding CdSe nanomaterials into a polymethyl methacrylate (PMMA) microfiber. It is incorporated into an EDFL cavity to generate a Q-switched laser operating at 1533.6nm. The repetition rates of the produced pulse train are tunable within 37–64kHz as the pump power is varied from 34mW to 74mW. The corresponding pulse width reduces from 7.96μs to 4.84μs, and the maximum pulse energy of 1.16nJ is obtained at the pump power of 74mW.
文摘A stable Q-switched erbium doped fiber laser emitting at 1558 nm is demonstrated using a cadmium selenide(CdSe) material coated onto a side-polished D-shape fiber as the saturable absorber(SA). By elevating the input pump power from the threshold of 91 mW to the maximum available power of 136 mW, a pulse train with a maximum repetition rate of 57.44 kHz, minimum pulse width of 3.76 us, maximum average output power of7.99 mW, maximum pulse energy of 0.1391 uJ, and maximum peak power of 36.99 mW are obtained. The signalto-noise ratio of the spectrum is measured to be around 75 dB. This CdSe based SA is simple, robust, and reliable,and thus suitable for making a portable pulse laser source.
文摘A mode-locked erbium doped fiber laser(EDFL) is demonstrated using the vanadium oxide(V2O5) material as a saturable absorber(SA). The V2O5 based SA is hosted into poly ethylene oxide film and attached on fiber ferule in the laser cavity. It shows 7% modulation depth with 71 MW/cm2 saturation intensity. By incorporating the SA inside the EDFL cavity with managed intra-cavity dispersion, ultrashort soliton pulses are successfully generated with a full width at half maximum of 3.14 ps. The laser operated at central wavelength of 1559.25 nm and repetition frequency of 1 MHz.
文摘We demonstrate a femtosecond mode-locked erbium-doped fiber laser(EDFL) using a nickel oxide(Ni O) as a saturable absorber(SA). Ni O nanoparticles are hosted into polyethylene oxide film and attached to fiber ferrule in the laser cavity. The Ni O-SA shows a 39% modulation depth with a 0.04 MW∕cm^2 saturation intensity. Our ring laser cavity based on erbium-doped active fiber with managed intracavity dispersion has the ability to generate ultrashort pulses with a full width at half-maximum(FWHM) of around 2.85 nm centered at 1561.8 nm.The pulses repeat at a frequency of 0.96 MHz and duration of 950 fs.
基金Supported by the University of Malaya under Grant No PG173-2015B
文摘We demonstrate an ultrafast fiber laser based on transition metal dichalcogenide materials which are tungsten disulfide (WS<sub>2</sub>) and molybdenum disulfide (MoS<sub>2</sub>) as saturable absorber (SA). These materials are fabricated via a simple drop-casting method. By employing WS<sub>2</sub>, we obtain a stable harmonic mode-locking at the threshold pump power of 184 mW, and the generated soliton pulse has 3.48 MHz of repetition rate. At the maximum pump power of 250 mW, we also obtain a small value of pulse duration, 2.43 ps with signal-to-noise ratio (SNR) of 57 dB. For MoS<sub>2</sub> SA, the pulse is generated at 105 mW pump power with repetition rate of 1.16 MHz. However, the pulse duration cannot be detected by the autocorrelator device as the pulse duration recorded is 468 ns, with the SNR value of 35 dB.
文摘BACKGROUND Primary synovial chondromatosis(PSC) is a rare arthropathy of the synovial joints characterized by the formation of cartilaginous nodules, which may detach and become loose bodies within the joint and may undergo secondary proliferation. PSC of the foot and ankle is exceedingly rare, with only a few cases reported in the literature. The diagnosis may be difficult and delayed until operative treatment, when it is confirmed by histological assessment. PSC may degenerate into chondrosarcoma. Operative treatment is the gold standard aiming to minimize pain, improve function, prevent or limit progression of arthritis. Surgical treatment consists in debridement by arthrotomic or arthroscopic management, but there is no consensus in the literature about timing of surgery and surgical technique. Thus, the aim of this study is to report the outcomes of the surgical treatment of two cases, together with a literature review.CASE SUMMARY We report two cases of patients affected by PSC of the foot in stage III, according to the Milgram classification: the former PSC localized in the ankle that underwent open surgery consisted of loose bodies removal;the latter in the subtalar joint, and the choice of treatment was the arthrotomy and debridement from loose bodies, in addition to the subtalar arthrodesis. Both patients returned to complete daily and working life after surgery.CONCLUSION Synovial chondromatosis is a rare benign pathology, even rarer in the ankle joint and especially in the foot. Surgery should be minimal in patients with ankle PSC,choosing the correct timing, waiting if possible until stage III. More aggressive and early surgery should be performed in patients with PSC of the foot,particularly the subtalar joint, due to the high risk of arthritic evolution.
文摘We demonstrate a Q-switched Raman fiber laser using molybdenum disulfide (MoS2) as a saturable absorber (SA). The SA is assembled by depositing a mechanically exfoliated MoS2 onto a fiber ferrule facet before it is matched with another clean ferrule via a connector. It is inserted in a Raman fiber laser cavity with a total cavity length of about 8kin to generate a Q-switching pulse train operating at 1560.2nm. A 7.7-kin-long dispersion compensating fiber with 584 ps.nm-i km-1 of dispersion is used as a nonlinear gain medium. As the pump power is increased from 395 m W to 422 m W, the repetition rate of the Q-switching pulses can be increased from 132.7 to 137.4 kHz while the pulse width is concurrently decreased from 3.35μs to 3.03μs. The maximum pulse energy of 54.3 nJ is obtained at the maximum pump power of 422 roW. These results show that the mechanically exfoliated MoS2 SA has a great potential to be used for pulse generation in Raman fiber laser systems.
文摘Dear Sir,Triamcinolone acetonide(TA)is worldwide available therapeutic agent that is commonly used throughout medicine.TA remains a safe and important ophthalmic therapeutic agent even after the advent of angiogenesis inhibitors[1-2].
基金Supported by the University of Malaya under Grant No PG100-2014B
文摘We demonstrate a Q-switched ytterbium-doped fiber laser (YDFL) using a newly developed multi-layer black phosphorous (BP) saturable absorber (SA). The BP SA is prepared by mechanically exfoliating a BP crystal and sticking the acquired BP flakes onto a scotch tape. A small piece of the tape is then placed between two ferrules and incorporated in a YDFL cavity to achieve a stable Q-switched operation in a 1.0 μm region. The laser has a pump threshold of 55.1 mW, a pulse repetition rate that is tunable from 8.2 to 32.9 kHz, and the narrowest pulse width of 10.8 μs. The highest pulse energy of 328 nJ is achieved at the pump power of 97.6 mW. Our results show that multi-layer BP is a promising SA for Q-switching laser operation.
基金supported by the Ministry of Education Malaysia,Universiti Teknologi Malaysia and RUG vote 11H60
文摘This paper presents a collaborative beamforming (CB) technique to organize the sensor node's location in a linear array for green wireless sensor network (WSN) applications. In this method, only selected clusters and active CB nodes are needed each time to perform CB in WSNs. The proposed least-square linear array (LSLA) manages to select nodes to perform as a linear antenna array (LAA), which is similar to and as outstanding as the conventional uniform linear array (ULA). The LSLA technique is also able to solve positioning error problems that exist in the random nodes deployment. The beampattern fluctuations have been analyzed due to the random positions of sensor nodes. Performances in terms of normalized power gains are given. It is demonstrated by a simulation that the proposed technique gives similar performances to the conventional ULA and at the same time exhibits lower complexity.
基金support of the Research Management Centre(RMC)Universiti Teknologi Malaysia with the research grant(QJ 130000.2451.07G48)We would like to express our sincere thanks to all researchers who devoted their time and knowledge to the completeness of this research project。
文摘Cloud internet of things(IoT)is an emerging technology that is already impelling the daily activities of our lives.However,the enormous resources(data and physical features of things)generated from Cloud-enabled IoT sensing devices are lacking suitable managerial approaches.Existing research surveys on Cloud IoT mainly focused on its fundamentals,definitions and layered architecture as well as security challenges.Going by the current literature,none of the existing researches is yet to provide a detailed analysis on the approaches deployed to manage the heterogeneous and dynamic resource data generated by sensor devices in the cloud-enabled IoT paradigm.Hence,to bridge this gap,the existing algorithms designed to manage resource data on various CloudloT application domains are investigated and analyzed.The emergence of CloudloT,followed by previous related survey articles in this field,which motivated the current study is presented.Furthermore,the utilization of simulation environment,highlighting the programming languages and a brief description of the simulation pack-ages adopted to design and evaluate the performance of the algorithms are examined.The utilization of diverse network communication protocols and gateways to aid resource dissemina-tion in the cloud-enabled IoT network infrastructure are also discussed.The future work as discussed in previous researches,which pave the way for future research directions in this field is also presented,and ends with concluding remarks.
基金supported by the Ministry of Higher Education Malaysia Grant Scheme(FRGS/1/2015/SG02/UITM/03/3)
文摘We demonstrate the generation of mode-locked pulses in an erbium-doped fiber laser(EDFL) by using a new manganese-doped cadmium selenide quantum-dots-based saturable absorber. The laser produces a soliton pulse train operating at 1561.1 nm with a repetition rate of 1 MHz, as the pump power is varied from 113 to 250 m W.At the maximum pump power, we obtain the pulse duration of 459 ns with a signal-to-noise ratio of 50 dB.
文摘A retrospective analysis was performed of patients who received a paracentesis immediately following an intravitreal injection of bevacizumab or triamcinolone acetonide.These patients were previously diagnosed as having glaucoma,ocular hypertension,or had responded previously with sustained elevated intraocular pressure.Of 1661 procedures were performed.Totally 219(13%) of the injections were on phakic patients.A median(SD) of 210 μL(40 μL) of aqueous was removed during each paracentesis.There were no reported incidences of any complications.We propose performing a paracentesis immediately following intravitreal injections for patients at risk for ocular hypertension,glaucoma,and retinal vein or artery occlusion.
基金Supported by the University of Malaya under Grant No PG173-2015B
文摘We demonstrate a Q-switched erbium-doped fiber laser (EDFL) using a newly developed zinc oxide- (ZnO) based saturable absorber (SA). The SA is fabricated by embedding a prepared ZnO powder into a poly(vinyl alcohol) film. A small piece of the film is then sandwiched between two fiber ferrules and is incorporated in an EDFL cavity for generating a stable Q-switching pulse train. The EDFL operates at 1560.4nm with a pump power threshold of 11.8mW, a pulse repetition rate tunable from 22.79 to 61.43kHz, and the smallest pulse width of 7.00 μs. The Q-switching pulse shows no spectral modulation with a peak-to-pedestal ratio of 62 dB indicating the high stability of the laser. These results show that the ZnO powder has a great potential to be used for pulsed laser applications.