Effects of photoinhibition and its recovery on photosynthetic functions of winter wheat (Triticum aestivum L.) under salt stress were studied. The results showed that several parameters associated with PSⅡ functions,...Effects of photoinhibition and its recovery on photosynthetic functions of winter wheat (Triticum aestivum L.) under salt stress were studied. The results showed that several parameters associated with PSⅡ functions, e.g. Fv/Fo?Fv/Fm and qP were not influenced by lower salt concentration (200 mmol/L NaCl) while CO 2 assimilation rate decreased significantly. When exposed to higher salt concentration (400 mmol/L NaCl), PSⅡ functions were significantly inhibited which led to the decrease of carbon assimilation. These results suggest that different concentrations of salt stress affected photosynthesis by different modes. Salt stress made photosynthesis more sensitive to strong light and led to more serious photoinhibition. Under lower concentration of salt stress, the Q B-non-reductive PSⅡ reaction centers formed at the beginning of photoinhibition could be effectively used to compose active PSⅡ reaction center (RC) and repair the reversible inactivated PSⅡ RC. Under higher concentration of salt stress, PSⅡ reaction centers were seriously damaged during photoinhibition, the Q B-non-reductive PSⅡ RC could only be partly effective at the early time of photoinhibition, thus led to the accumulation of Q B-non-reductive PSⅡ RC in the course of restoration under dim light.展开更多
A new approach for the design and implementation of a programmable voltage reference based on an improved current mode bandgap voltage reference is presented. The circuit is simulated and fabricated with Chartered 0....A new approach for the design and implementation of a programmable voltage reference based on an improved current mode bandgap voltage reference is presented. The circuit is simulated and fabricated with Chartered 0. 35μm mixed-signal technology. Measurements demonstrate that the temperature coefficient is ± 36. 3ppm/℃ from 0 to 100℃ when the VID inputs are 11110.As the supply voltage is varied from 2.7 to 5V, the voltage reference varies by about 5mV. The maximum glitch of the transient response is about 20mV at 125kHz. Depending on the state of the five VID inputs,an output voltage between 1.1 and 1.85V is programmed in increments of 25mV.展开更多
Learned association between context and drug abuse is essential for the drug conditioned place preference (CPP), which is an animal model widely used to measure drug reward. Synaptic plasticity, in the form of long-...Learned association between context and drug abuse is essential for the drug conditioned place preference (CPP), which is an animal model widely used to measure drug reward. Synaptic plasticity, in the form of long-term potentiation (LTP) and depression (LTD), is regarded as a proposed cellular substrate of learning and memory. However, the exact role of LTP/LTD in addiction is not known yet. Therefore, by bioinformatics we designed peptides aiming to interfere with LTP and LTD respectively, to study their individual role in the expression of morphine CPP. We found that the interfering peptide Pep-A2 can specifically block hippocampal LTP in CA1 region, whereas Pep-A3 can block LTD in this region. Treatment of either of their cell penetrating forms (Tat-A2 or Tat-A3) before test can block the expression of Morphine CPP in mice. These results suggested that both LTP and LTD are required in the drug-associated learning and memory.展开更多
The floatability of diaspore and three kinds of silicate minerals,including kaolinite,illite and pyrophyllite,by a cationic Gemini surfactant as collector and starch as depressant was investigated as function of reage...The floatability of diaspore and three kinds of silicate minerals,including kaolinite,illite and pyrophyllite,by a cationic Gemini surfactant as collector and starch as depressant was investigated as function of reagents concentration and pulp pH.Further studies of artificially mixed minerals and bauxite ore were also detailedly conducted.At last,the pre-desliming reverse flotation separation process was adopted.It can be concluded that the combinational use of a Gemini cationic collector and the starch depressant is effective.The concentrates with Al2O3 to SiO2 mass ratio of 9.66 and the recovery of Al2O3 of 71.73% are obtained from natural bauxite ore(A/S=5.70) at pH value of around 10.展开更多
It is well-known that the IMC-PID controller tuning gives fast and improved set point response but slow disturbance rejection. A modification has been proposed in IMC-PID tuning rule for the improved disturbance rejec...It is well-known that the IMC-PID controller tuning gives fast and improved set point response but slow disturbance rejection. A modification has been proposed in IMC-PID tuning rule for the improved disturbance rejection. For the modified IMC-PID tuning rule, a method has been developed to obtain the IMC-PID setting in closed-loop mode without acquiring detailed information of the process. The proposed method is based on the closed-loop step set point experiment using a proportional only controller with gain K_(c0). It is the direct approach to find the PID controller setting similar to classical Ziegler-Nichols closed-loop method. Based on simulations of a wide range of first-order with delay processes, a simple correlation has been derived to obtain the modified IMC-PID controller settings from closed-loop experiment. In this method, controller gain is a function of the overshoot obtained in the closed loop set point experiment. The integral and derivative time is mainly a function of the time to reach the first peak(overshoot). Simulation has been conducted for the broad class of processes and the controllers were tuned to have the same degree of robustness by measuring the maximum sensitivity, Ms, in order to obtain a reasonable comparison. The PID controller settings obtained in the proposed tuning method show better performance and robustness with other two-step tuning methods for the broad class of processes. It has also been applied to temperature control loop in distillation column model. The result has been compared to the open loop tuning method where it gives robust and fast response.展开更多
The corrosion inhibition of mild steel in 1 mol/L HC1 by N, N'-bis (2-hydroxybenzaldehyde)- 1, 3-propandiimine (2-HBP) has been investigated by using potentiodynamic polarization, electrochemical impedance spectr...The corrosion inhibition of mild steel in 1 mol/L HC1 by N, N'-bis (2-hydroxybenzaldehyde)- 1, 3-propandiimine (2-HBP) has been investigated by using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and chronoamperometry measurements. The experimental results suggest that this compound is an excellent corrosion inhibitor for mild steel and the inhibition efficiency increases with the increase in inhibitor concentration. Polarization curves reveal that this organic compound is a mixed type inhibitor. The effect of temperature on the corrosion behavior of mild steel with the addition of the Schiff base was studied in the temperature range from 25 ℃ to 65℃. The experimentally obtained adsorption isotherms follow the Langmuir equation. Activation and thermodynamic adsorption parameters such as Ea, △H, △S,Kads and AG,ds were calculated by the corrosion currents at different temperatures and using the adsorption isotherm. The morphology of mild steel surface in the absence and presence of 2-HBP was examined by atomic force microscope (AFM) images.展开更多
In this paper, we present the decoupling bang-bang (BB) twin-born pulses to suppress the genera/deco- herence, both amplitude and phase decoherence, in a three-level atom in V- and Ξ-configurations. We give the exa...In this paper, we present the decoupling bang-bang (BB) twin-born pulses to suppress the genera/deco- herence, both amplitude and phase decoherence, in a three-level atom in V- and Ξ-configurations. We give the exact sequence of periodic twinborn pulses in such systems.展开更多
On augmentation of past work, an effective Wiener filter and its application for noise suppression combined with a formed CORDIC based FFT/IFFT processor with improved speed were executed. The pipelined methodology wa...On augmentation of past work, an effective Wiener filter and its application for noise suppression combined with a formed CORDIC based FFT/IFFT processor with improved speed were executed. The pipelined methodology was embraced for expanding the execution of the system. The proposed Wiener filter was planned in such an approach to evacuate the iteration issues in ordinary Wiener filter. The division process was supplanted by a productive inverse and multiplication process in the proposed design. An enhanced design for matrix inverse with reduced computation complexity was executed. The wide-ranging framework processing was focused around IEEE-754 standard single precision floating point numbers. The Wiener filter and the entire system design was integrated and actualized on VIRTEX 5 FPGA stage and re-enacted to approve the results in Xilinx ISE 13.4. The results show that a productive decrease in power and area is developed by adjusting the proposed technique for speech signal noise degradation with latency of n/2 clock cycles and substantial throughput result per every 12 clock cycles for n-bit precision. The execution of proposed design is exposed to be 31.35% more effective than that of prevailing strategies.展开更多
The optimal control design for singularly perturbed time-delay systems affected by external distur-bances is considered.Based on the decomposition theory of singular perturbation,the system is decom-posed into a fast ...The optimal control design for singularly perturbed time-delay systems affected by external distur-bances is considered.Based on the decomposition theory of singular perturbation,the system is decom-posed into a fast subsystem without time-delay and a slow time-delay subsystem with disturbances.Theoptimal disturbances rejection control law of the slow subsystem is obtained by using the successive ap-proximation approach(SAA)and feedforward compensation method.Further,the feedforward and feed-back composite control(FFCC)law for the original problem is developed.The FFCC law consists of lin-ear analytic terms and a time-delay compensation term which is the limit of the solution sequence of theadjoint vector equations.A disturbance observer is introduced to make the FFCC law physically realiz-able.Numerical examples show that the proposed algorithm is effective.展开更多
Quantitatively-measuring of coal dust wettability is essential for the R/D of chemical coal dust suppressants in the field of dust control with wetting-agent-added water. Analysed the causes which in present lab testi...Quantitatively-measuring of coal dust wettability is essential for the R/D of chemical coal dust suppressants in the field of dust control with wetting-agent-added water. Analysed the causes which in present lab testing of coal dust wettability cause out-comes' low repeat rate and poor consistency with coal dust suppression practices in fields, and investigated the influence of different briquetting pressure (from 0 to 6.5×10^8 Pa) on the wet behavior of coal dust as a new way to evaluate quantitatively coal dust wettability. The study shows that there is a fairly high coincidence between the coal dust wettability data measured by briquetting technique and the results gained from the lab dust suppression tests using an apparatus MCYZ.展开更多
AIM: To understand which and how different miRNAs are implicated in the process of hepatic stellate cell (HSC) activation. METHODS: We used microarrays to examine the differential expression of miRNAs during in vitro ...AIM: To understand which and how different miRNAs are implicated in the process of hepatic stellate cell (HSC) activation. METHODS: We used microarrays to examine the differential expression of miRNAs during in vitro activation of primary HSCs (pHSCs). The transcriptome changes upon stable transfection of rno-miR-146a into an HSC cell line were studied using cDNA microarrays. Selected differentially regulated miRNAs were investigated by quantitative real-time polymerase chain reaction during in vivo HSC activation. The effect of miRNA mimics and inhibitor on the in vitro activation of pHSCs was also evaluated.RESULTS: We found that 16 miRNAs were upregulated and 26 were downregulated significantly in 10-d in vitro activated pHSCs in comparison to quiescent pHSCs. Overexpression of rno-miR-146a was characterized by marked upregulation of tissue inhibitor of metalloproteinase-3, which is implicated in the regulation of tumor necrosis factor-α activity. Differences in the regulation of selected miRNAs were observed comparing in vitro and in vivo HSC activation. Treatment with miR-26a and 29a mimics, and miR-214 inhibitor during in vitro activation of pHSCs induced significant downregulation of collagen type Ⅰ transcription. CONCLUSION: Our results emphasize the different regulation of miRNAs in in vitro and in vivo activated pHSCs. We also showed that miR-26a, 29a and 214 are involved in the regulation of collagen type I mRNA.展开更多
Adopting oil-bath temperature programming experiment and gas chromatography, CO2's inhibitory performance on spontaneous combustion of Tingnan Coal Mine sample was analyzed. Through temperature rise rate test experim...Adopting oil-bath temperature programming experiment and gas chromatography, CO2's inhibitory performance on spontaneous combustion of Tingnan Coal Mine sample was analyzed. Through temperature rise rate test experiment, the accuracy, stability and reliability of the improved oil-bath temperature programming system applied in this experiment was proved to be superior to the traditional system. Spontaneous combustion characters parameters test of coal sample in pure air was carried out with this system and offered comparison standard for research in next stage. Temperature programming to coal sample was further conducted in oil-bath with different concentration of CO2. Testing results are compared with parameters of concentration of CO, O2, temperature, CO generation rate and O2 consumption rate tested and calculated in previous experiment in pure air. Methods of proportioning between concentration of CO and O2, CO concentration and temperature, CO generation rate and O2 consumption rate were applied to eliminate obstructions from certain external factors such as inlet of CO2; meanwhile influences of CO2 of different concentrations to coal oxidation and spontaneous combustion were investigated. Also CO2 inhibition technique was used in spontaneous combustion prevention in workface No. 106 of Tingnan Coal Mine, data collected from which indicate that CO2 performs well in inhibiting coal oxidation and spontaneous combustion.展开更多
This paper presents a new genetic algorithm for the resource-constrained project scheduling problem(RCPSP).The algorithm employs a standardized random key(SRK) vector representation with an additional gene that determ...This paper presents a new genetic algorithm for the resource-constrained project scheduling problem(RCPSP).The algorithm employs a standardized random key(SRK) vector representation with an additional gene that determines whether the serial or parallel schedule generation scheme(SGS) is to be used as the decoding procedure.The iterative forward-backward improvement as the local search procedure is applied upon all generated solutions to schedule the project three times and obtain an SRK vector,which is rese...展开更多
Wnt signaling has been shown to engage a multifunctional pathway that is involved in the regulation of a wide variety of normal and pathologic processes, including embryogenesis, differentiation and tumorigenesis. Rec...Wnt signaling has been shown to engage a multifunctional pathway that is involved in the regulation of a wide variety of normal and pathologic processes, including embryogenesis, differentiation and tumorigenesis. Recent studies have demonstrated that Wnt5a expression is frequently seen in various human cancers. In contrast to the transforming members of the Wnt family, shown to be upregulated in many cancers, the role of Wnt5a is still controversial in its expression in different tumors. There is increasing evidence that Wnt5a has tumor suppressor function in some malignancies, and in addition, it elicits promigratory and proinvasive effects via the planar cell polarity pathway, which suggests that Wnt5a might be an effective marker for the progression and prognosis of tumors. Obviously, the outcome of Wnt5a signaling is dependent on a multitude of variables, ranging from receptors, downstream effectors and inhibitors, to external influences coming from the tumor microenvironment. This review will focus on the role of Wnt5a signaling and, as a consequence, provide an outline describing the expression and functions of Wnt5a in cancer progression.展开更多
Gastrin is the main hormone responsible for the stimulation of gastric acid secretion;in addition,gastrin and its derivatives exert proliferative and antiapoptotic effects on several cell types.Gastrin synthesis and s...Gastrin is the main hormone responsible for the stimulation of gastric acid secretion;in addition,gastrin and its derivatives exert proliferative and antiapoptotic effects on several cell types.Gastrin synthesis and secretion are increased in certain situations,for example,when proton pump inhibitors are used.The impact of sustained hypergastrinemia is currently being investigated.In vitro experiments and animal models have shown that prolonged hypergastrinemia may be related with higher cancer rates;although,this relationship is less clear in human beings.Higher gastrin levels have been shown to cause hyperplasia of several cell types;yet,the risk for developing cancer seems to be the same in normo-and hypergastrinemic patients.Some tumors also produce their own gastrin,which can act in an autocrine manner promoting tumor growth.Certain cancers are extremely dependent on gastrin to proliferate.Initial research focused only on the effects of amidated gastrins,but there has been an interest in intermediates of gastrin in the last few decades.These intermediates aren't biologically inactive;in fact,they may exert greater effects on proliferation and apoptosis than the completely processed forms.In certain gastrin overproduction states,they are the most abundant gastrin peptides secreted.The purpose of this review is to examine the gastrin biosynthesis process and to summarize the results from different studies evaluating the production,levels,and effects of the main forms of gastrin in different overexpression states and their possible relationship with Barrett's and colorectal carcinogenesis.展开更多
AIM:To examine the relative prevalence and temporal variation of dysphagia etiologies in patients undergoing upper endoscopy(EGD) over the past decade.METHODS:EGDs with the indication of dysphagia at an urban,universi...AIM:To examine the relative prevalence and temporal variation of dysphagia etiologies in patients undergoing upper endoscopy(EGD) over the past decade.METHODS:EGDs with the indication of dysphagia at an urban,university medical center in 1999,2004 and 2009 were retrospectively identified from the electronic medical record.The entire patient chart,including EGD,pathology,manometry,radiographic and clinician reports,was reviewed for demographic and clinical data and to determine the etiology of dysphagia.The number of EGDs in which an esophageal biopsy was performed was also noted.Gastroesophageal reflux disease(GERD) as a cause of dysphagia independent of peptic stricture was defined by symptoms with erosive esophagitis or symptom response to proton pump inhibition(PPI).Cases of eosinophilic esophagitis(EoE) were defined by an appropriate clinical history and histological criteria of ≥ 15 eosinophils per high powered field.PPI-responsive esophageal eosinophilia was not routinely reported prior to 2008.Statistical analysis was performed using one-way analysis of variance to analyze for trends between 1999,2004 and 2009 and a post-hoc Tukey analysis was performed following a significant main effect.RESULTS:A total of 1371 cases(mean age 54 years,43% male) met pre-specified inclusion criteria with 191,504 and 675 cases in 1999,2004 and 2009,respectively.Patients were older in 2004 compared to 2009(mean ± SD,54.0 ± 15.7 years vs 52.3 ± 16.8 years,P = 0.02) and there were more males in 1999 compared to 2004(57.5% vs 40.8%,P = 0.005).Overall,GERD(27.6%) and EoE(7.7%) were the most common identifiable causes of dysphagia.An unspecified diagnosis accounted for 21% of overall cases.There were no significant differences in the relative prevalence of achalasia or other motility disorders,peptic stricture,Schatzki's ring,esophageal cancer or unspecified diagnoses over the 10-year time period.There was,however,a decrease in the relative prevalence of GERD(39.3% vs 24.1%,P < 0.001) and increases in the relative prevalence of EoE(1.6% vs 11.2%,P < 0.001) and oropharyngeal disorders(1.6% vs 4.2%,P = 0.02) from 1999 to 2009.Post-hoc analyses determined that the increase in relative prevalence of EoE was significant between 1999 and 2009 as well as 2004 and 2009(5.4% vs 11.6%,P < 0.001),but not between 1999 and 2004(1.6% P 5.4%,P = 0.21).On the other hand,the decrease in relative prevalence of GERD was significant between 1999 and 2009 and 1999 and 2004(39.3% vs 27.7%,P = 0.006),but not between 2004 and 2009(27.7% vs 24.1%,P = 0.36).There were also significantly more EGDs in which a biopsy was obtained in 1999 compared to 2009(36.7% vs 68.7%,P < 0.001) as well as between 2004 and 2009(37.5% vs 68.7%,P < 0.001).While total EGD volume did increase over the 10-year time period,the percentage of EGDs for the indication of dysphagia remained stable making increasing upper endoscopy an unlikely reason for the observed increased prevalence of EoE.CONCLUSION:EoE has emerged as a dominant cause of dysphagia in adults.Whether this was due to a rise in disease incidence or increased recognition is unclear.展开更多
文摘Effects of photoinhibition and its recovery on photosynthetic functions of winter wheat (Triticum aestivum L.) under salt stress were studied. The results showed that several parameters associated with PSⅡ functions, e.g. Fv/Fo?Fv/Fm and qP were not influenced by lower salt concentration (200 mmol/L NaCl) while CO 2 assimilation rate decreased significantly. When exposed to higher salt concentration (400 mmol/L NaCl), PSⅡ functions were significantly inhibited which led to the decrease of carbon assimilation. These results suggest that different concentrations of salt stress affected photosynthesis by different modes. Salt stress made photosynthesis more sensitive to strong light and led to more serious photoinhibition. Under lower concentration of salt stress, the Q B-non-reductive PSⅡ reaction centers formed at the beginning of photoinhibition could be effectively used to compose active PSⅡ reaction center (RC) and repair the reversible inactivated PSⅡ RC. Under higher concentration of salt stress, PSⅡ reaction centers were seriously damaged during photoinhibition, the Q B-non-reductive PSⅡ RC could only be partly effective at the early time of photoinhibition, thus led to the accumulation of Q B-non-reductive PSⅡ RC in the course of restoration under dim light.
文摘A new approach for the design and implementation of a programmable voltage reference based on an improved current mode bandgap voltage reference is presented. The circuit is simulated and fabricated with Chartered 0. 35μm mixed-signal technology. Measurements demonstrate that the temperature coefficient is ± 36. 3ppm/℃ from 0 to 100℃ when the VID inputs are 11110.As the supply voltage is varied from 2.7 to 5V, the voltage reference varies by about 5mV. The maximum glitch of the transient response is about 20mV at 125kHz. Depending on the state of the five VID inputs,an output voltage between 1.1 and 1.85V is programmed in increments of 25mV.
基金supported by the National Natural Science Foundation of China(3053025030623007)
文摘Learned association between context and drug abuse is essential for the drug conditioned place preference (CPP), which is an animal model widely used to measure drug reward. Synaptic plasticity, in the form of long-term potentiation (LTP) and depression (LTD), is regarded as a proposed cellular substrate of learning and memory. However, the exact role of LTP/LTD in addiction is not known yet. Therefore, by bioinformatics we designed peptides aiming to interfere with LTP and LTD respectively, to study their individual role in the expression of morphine CPP. We found that the interfering peptide Pep-A2 can specifically block hippocampal LTP in CA1 region, whereas Pep-A3 can block LTD in this region. Treatment of either of their cell penetrating forms (Tat-A2 or Tat-A3) before test can block the expression of Morphine CPP in mice. These results suggested that both LTP and LTD are required in the drug-associated learning and memory.
基金Project(50874118) supported by the National Natural Science Foundation of ChinaProject(2007B52) supported by the Foundation for the Author of National Excellent Doctoral Dissertation of ChinaProject(2005CB623701) supported by the National Basic Research Program of China
文摘The floatability of diaspore and three kinds of silicate minerals,including kaolinite,illite and pyrophyllite,by a cationic Gemini surfactant as collector and starch as depressant was investigated as function of reagents concentration and pulp pH.Further studies of artificially mixed minerals and bauxite ore were also detailedly conducted.At last,the pre-desliming reverse flotation separation process was adopted.It can be concluded that the combinational use of a Gemini cationic collector and the starch depressant is effective.The concentrates with Al2O3 to SiO2 mass ratio of 9.66 and the recovery of Al2O3 of 71.73% are obtained from natural bauxite ore(A/S=5.70) at pH value of around 10.
基金the support provided by King Abdulaziz City for Science and Technology (KACST) through the Science & Technology Unit at King Fahd University of PetroleumMinerals (KFUPM) for funding this work through project number 11-ENE1643-04 as part of the Notional Science Technology and Innovation Plan
文摘It is well-known that the IMC-PID controller tuning gives fast and improved set point response but slow disturbance rejection. A modification has been proposed in IMC-PID tuning rule for the improved disturbance rejection. For the modified IMC-PID tuning rule, a method has been developed to obtain the IMC-PID setting in closed-loop mode without acquiring detailed information of the process. The proposed method is based on the closed-loop step set point experiment using a proportional only controller with gain K_(c0). It is the direct approach to find the PID controller setting similar to classical Ziegler-Nichols closed-loop method. Based on simulations of a wide range of first-order with delay processes, a simple correlation has been derived to obtain the modified IMC-PID controller settings from closed-loop experiment. In this method, controller gain is a function of the overshoot obtained in the closed loop set point experiment. The integral and derivative time is mainly a function of the time to reach the first peak(overshoot). Simulation has been conducted for the broad class of processes and the controllers were tuned to have the same degree of robustness by measuring the maximum sensitivity, Ms, in order to obtain a reasonable comparison. The PID controller settings obtained in the proposed tuning method show better performance and robustness with other two-step tuning methods for the broad class of processes. It has also been applied to temperature control loop in distillation column model. The result has been compared to the open loop tuning method where it gives robust and fast response.
文摘The corrosion inhibition of mild steel in 1 mol/L HC1 by N, N'-bis (2-hydroxybenzaldehyde)- 1, 3-propandiimine (2-HBP) has been investigated by using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and chronoamperometry measurements. The experimental results suggest that this compound is an excellent corrosion inhibitor for mild steel and the inhibition efficiency increases with the increase in inhibitor concentration. Polarization curves reveal that this organic compound is a mixed type inhibitor. The effect of temperature on the corrosion behavior of mild steel with the addition of the Schiff base was studied in the temperature range from 25 ℃ to 65℃. The experimentally obtained adsorption isotherms follow the Langmuir equation. Activation and thermodynamic adsorption parameters such as Ea, △H, △S,Kads and AG,ds were calculated by the corrosion currents at different temperatures and using the adsorption isotherm. The morphology of mild steel surface in the absence and presence of 2-HBP was examined by atomic force microscope (AFM) images.
基金The project supported by the National Fundamental Research Program under Grant No.2006CB921106National Natural Science Foundation of China under Grant Nos.10325521,60433050,and 60635040+1 种基金the SRFDP Program of Education Ministry of China under Grant No.20060003048the Key Project of the Ministry of Education of China under Grant No.306020
文摘In this paper, we present the decoupling bang-bang (BB) twin-born pulses to suppress the genera/deco- herence, both amplitude and phase decoherence, in a three-level atom in V- and Ξ-configurations. We give the exact sequence of periodic twinborn pulses in such systems.
文摘On augmentation of past work, an effective Wiener filter and its application for noise suppression combined with a formed CORDIC based FFT/IFFT processor with improved speed were executed. The pipelined methodology was embraced for expanding the execution of the system. The proposed Wiener filter was planned in such an approach to evacuate the iteration issues in ordinary Wiener filter. The division process was supplanted by a productive inverse and multiplication process in the proposed design. An enhanced design for matrix inverse with reduced computation complexity was executed. The wide-ranging framework processing was focused around IEEE-754 standard single precision floating point numbers. The Wiener filter and the entire system design was integrated and actualized on VIRTEX 5 FPGA stage and re-enacted to approve the results in Xilinx ISE 13.4. The results show that a productive decrease in power and area is developed by adjusting the proposed technique for speech signal noise degradation with latency of n/2 clock cycles and substantial throughput result per every 12 clock cycles for n-bit precision. The execution of proposed design is exposed to be 31.35% more effective than that of prevailing strategies.
基金the National Natural Science Foundation of China(No.60574023,40776051)the Natural Science Foundation of Zhejiang Province(No.Y107232)+1 种基金the Scientific Research Found of Zhejiang Provincial Education Department(No.Y200702660)the 123 Talent Funding Project of China Jiliang University(No.2006RC17)
文摘The optimal control design for singularly perturbed time-delay systems affected by external distur-bances is considered.Based on the decomposition theory of singular perturbation,the system is decom-posed into a fast subsystem without time-delay and a slow time-delay subsystem with disturbances.Theoptimal disturbances rejection control law of the slow subsystem is obtained by using the successive ap-proximation approach(SAA)and feedforward compensation method.Further,the feedforward and feed-back composite control(FFCC)law for the original problem is developed.The FFCC law consists of lin-ear analytic terms and a time-delay compensation term which is the limit of the solution sequence of theadjoint vector equations.A disturbance observer is introduced to make the FFCC law physically realiz-able.Numerical examples show that the proposed algorithm is effective.
基金the National Natural Science Foundation of China(90210014)
文摘Quantitatively-measuring of coal dust wettability is essential for the R/D of chemical coal dust suppressants in the field of dust control with wetting-agent-added water. Analysed the causes which in present lab testing of coal dust wettability cause out-comes' low repeat rate and poor consistency with coal dust suppression practices in fields, and investigated the influence of different briquetting pressure (from 0 to 6.5×10^8 Pa) on the wet behavior of coal dust as a new way to evaluate quantitatively coal dust wettability. The study shows that there is a fairly high coincidence between the coal dust wettability data measured by briquetting technique and the results gained from the lab dust suppression tests using an apparatus MCYZ.
基金Supported by Institute of Bioengineering and Nanotechnology (Biomedical Research Council, Agency for Science, Technology and Research, Singapore)
文摘AIM: To understand which and how different miRNAs are implicated in the process of hepatic stellate cell (HSC) activation. METHODS: We used microarrays to examine the differential expression of miRNAs during in vitro activation of primary HSCs (pHSCs). The transcriptome changes upon stable transfection of rno-miR-146a into an HSC cell line were studied using cDNA microarrays. Selected differentially regulated miRNAs were investigated by quantitative real-time polymerase chain reaction during in vivo HSC activation. The effect of miRNA mimics and inhibitor on the in vitro activation of pHSCs was also evaluated.RESULTS: We found that 16 miRNAs were upregulated and 26 were downregulated significantly in 10-d in vitro activated pHSCs in comparison to quiescent pHSCs. Overexpression of rno-miR-146a was characterized by marked upregulation of tissue inhibitor of metalloproteinase-3, which is implicated in the regulation of tumor necrosis factor-α activity. Differences in the regulation of selected miRNAs were observed comparing in vitro and in vivo HSC activation. Treatment with miR-26a and 29a mimics, and miR-214 inhibitor during in vitro activation of pHSCs induced significant downregulation of collagen type Ⅰ transcription. CONCLUSION: Our results emphasize the different regulation of miRNAs in in vitro and in vivo activated pHSCs. We also showed that miR-26a, 29a and 214 are involved in the regulation of collagen type I mRNA.
文摘Adopting oil-bath temperature programming experiment and gas chromatography, CO2's inhibitory performance on spontaneous combustion of Tingnan Coal Mine sample was analyzed. Through temperature rise rate test experiment, the accuracy, stability and reliability of the improved oil-bath temperature programming system applied in this experiment was proved to be superior to the traditional system. Spontaneous combustion characters parameters test of coal sample in pure air was carried out with this system and offered comparison standard for research in next stage. Temperature programming to coal sample was further conducted in oil-bath with different concentration of CO2. Testing results are compared with parameters of concentration of CO, O2, temperature, CO generation rate and O2 consumption rate tested and calculated in previous experiment in pure air. Methods of proportioning between concentration of CO and O2, CO concentration and temperature, CO generation rate and O2 consumption rate were applied to eliminate obstructions from certain external factors such as inlet of CO2; meanwhile influences of CO2 of different concentrations to coal oxidation and spontaneous combustion were investigated. Also CO2 inhibition technique was used in spontaneous combustion prevention in workface No. 106 of Tingnan Coal Mine, data collected from which indicate that CO2 performs well in inhibiting coal oxidation and spontaneous combustion.
文摘This paper presents a new genetic algorithm for the resource-constrained project scheduling problem(RCPSP).The algorithm employs a standardized random key(SRK) vector representation with an additional gene that determines whether the serial or parallel schedule generation scheme(SGS) is to be used as the decoding procedure.The iterative forward-backward improvement as the local search procedure is applied upon all generated solutions to schedule the project three times and obtain an SRK vector,which is rese...
文摘Wnt signaling has been shown to engage a multifunctional pathway that is involved in the regulation of a wide variety of normal and pathologic processes, including embryogenesis, differentiation and tumorigenesis. Recent studies have demonstrated that Wnt5a expression is frequently seen in various human cancers. In contrast to the transforming members of the Wnt family, shown to be upregulated in many cancers, the role of Wnt5a is still controversial in its expression in different tumors. There is increasing evidence that Wnt5a has tumor suppressor function in some malignancies, and in addition, it elicits promigratory and proinvasive effects via the planar cell polarity pathway, which suggests that Wnt5a might be an effective marker for the progression and prognosis of tumors. Obviously, the outcome of Wnt5a signaling is dependent on a multitude of variables, ranging from receptors, downstream effectors and inhibitors, to external influences coming from the tumor microenvironment. This review will focus on the role of Wnt5a signaling and, as a consequence, provide an outline describing the expression and functions of Wnt5a in cancer progression.
基金Supported by Instituto de Salud Carlos Ⅲ with Grants FIS 08/1047 and CIBERehdInstituto de Salud Carlos Ⅲ FI10/00167, to Chueca E
文摘Gastrin is the main hormone responsible for the stimulation of gastric acid secretion;in addition,gastrin and its derivatives exert proliferative and antiapoptotic effects on several cell types.Gastrin synthesis and secretion are increased in certain situations,for example,when proton pump inhibitors are used.The impact of sustained hypergastrinemia is currently being investigated.In vitro experiments and animal models have shown that prolonged hypergastrinemia may be related with higher cancer rates;although,this relationship is less clear in human beings.Higher gastrin levels have been shown to cause hyperplasia of several cell types;yet,the risk for developing cancer seems to be the same in normo-and hypergastrinemic patients.Some tumors also produce their own gastrin,which can act in an autocrine manner promoting tumor growth.Certain cancers are extremely dependent on gastrin to proliferate.Initial research focused only on the effects of amidated gastrins,but there has been an interest in intermediates of gastrin in the last few decades.These intermediates aren't biologically inactive;in fact,they may exert greater effects on proliferation and apoptosis than the completely processed forms.In certain gastrin overproduction states,they are the most abundant gastrin peptides secreted.The purpose of this review is to examine the gastrin biosynthesis process and to summarize the results from different studies evaluating the production,levels,and effects of the main forms of gastrin in different overexpression states and their possible relationship with Barrett's and colorectal carcinogenesis.
文摘AIM:To examine the relative prevalence and temporal variation of dysphagia etiologies in patients undergoing upper endoscopy(EGD) over the past decade.METHODS:EGDs with the indication of dysphagia at an urban,university medical center in 1999,2004 and 2009 were retrospectively identified from the electronic medical record.The entire patient chart,including EGD,pathology,manometry,radiographic and clinician reports,was reviewed for demographic and clinical data and to determine the etiology of dysphagia.The number of EGDs in which an esophageal biopsy was performed was also noted.Gastroesophageal reflux disease(GERD) as a cause of dysphagia independent of peptic stricture was defined by symptoms with erosive esophagitis or symptom response to proton pump inhibition(PPI).Cases of eosinophilic esophagitis(EoE) were defined by an appropriate clinical history and histological criteria of ≥ 15 eosinophils per high powered field.PPI-responsive esophageal eosinophilia was not routinely reported prior to 2008.Statistical analysis was performed using one-way analysis of variance to analyze for trends between 1999,2004 and 2009 and a post-hoc Tukey analysis was performed following a significant main effect.RESULTS:A total of 1371 cases(mean age 54 years,43% male) met pre-specified inclusion criteria with 191,504 and 675 cases in 1999,2004 and 2009,respectively.Patients were older in 2004 compared to 2009(mean ± SD,54.0 ± 15.7 years vs 52.3 ± 16.8 years,P = 0.02) and there were more males in 1999 compared to 2004(57.5% vs 40.8%,P = 0.005).Overall,GERD(27.6%) and EoE(7.7%) were the most common identifiable causes of dysphagia.An unspecified diagnosis accounted for 21% of overall cases.There were no significant differences in the relative prevalence of achalasia or other motility disorders,peptic stricture,Schatzki's ring,esophageal cancer or unspecified diagnoses over the 10-year time period.There was,however,a decrease in the relative prevalence of GERD(39.3% vs 24.1%,P < 0.001) and increases in the relative prevalence of EoE(1.6% vs 11.2%,P < 0.001) and oropharyngeal disorders(1.6% vs 4.2%,P = 0.02) from 1999 to 2009.Post-hoc analyses determined that the increase in relative prevalence of EoE was significant between 1999 and 2009 as well as 2004 and 2009(5.4% vs 11.6%,P < 0.001),but not between 1999 and 2004(1.6% P 5.4%,P = 0.21).On the other hand,the decrease in relative prevalence of GERD was significant between 1999 and 2009 and 1999 and 2004(39.3% vs 27.7%,P = 0.006),but not between 2004 and 2009(27.7% vs 24.1%,P = 0.36).There were also significantly more EGDs in which a biopsy was obtained in 1999 compared to 2009(36.7% vs 68.7%,P < 0.001) as well as between 2004 and 2009(37.5% vs 68.7%,P < 0.001).While total EGD volume did increase over the 10-year time period,the percentage of EGDs for the indication of dysphagia remained stable making increasing upper endoscopy an unlikely reason for the observed increased prevalence of EoE.CONCLUSION:EoE has emerged as a dominant cause of dysphagia in adults.Whether this was due to a rise in disease incidence or increased recognition is unclear.