Background: Improving Water, Sanitation and Hygiene in health care settings is a critical prerequisite for achieving national health goals and Sustainable Development Goals (SDGs). The World Health Organization (WHO) ...Background: Improving Water, Sanitation and Hygiene in health care settings is a critical prerequisite for achieving national health goals and Sustainable Development Goals (SDGs). The World Health Organization (WHO) has set a target for each United Nations member state to reach by 2030. Each member state is required to reach by 2022, 2025 and 2030 at least 60%, 80% and 100%, respectively of basic level of service of the five elements which are water, sanitation, hygiene, waste management and environmental cleaning. Methods: This study aimed to evaluate and document the current state of basic water, sanitation, and hygiene services in all lower-level health care facilities in the Dar es Salaam region of Tanzania as of July 2022. A cross-sectional study was conducted in 99 public dispensaries in the Dar es Salaam region’s five councils: Ubungo, Kigamboni, Kinondoni and Temeke Municipalities, and Ilala City. The interviewee form and observational checklists were both digitalized using the Kobo tool software. The respondents were health care facility in-charges or nurse in-charges. Data were downloaded, validated, and imported to Stata version 15 for analysis. Results: The basic WASH level per JMP is far below the target in 2022. Each member state by 2022 is required to reach at least 60% of the basic level of service of each element. We found a low coverage of basic WASH in the 99 dispensaries included in this study. The basic WASH coverage was met in only 10 (10.1%) of the dispensaries, while the remaining 89 (89.9%) dispensaries fall on limited WASH services. Conclusion: This study revealed lower coverage of basic WASH services in dispensaries. An urgent need is required to improve the status of WASH in all the dispensaries and facilitate the provision of quality health care services, patient safety and reduce health care associated infections.展开更多
BACKGROUND Whether patients with compensated cirrhosis and low-level viremia(LLV)of hepatitis B should receive antiviral therapy(AVT)is still controversial,and published results are inconsistent.AIM To investigate the...BACKGROUND Whether patients with compensated cirrhosis and low-level viremia(LLV)of hepatitis B should receive antiviral therapy(AVT)is still controversial,and published results are inconsistent.AIM To investigate the link between LLV in compensated cirrhosis and prognosis concerning hepatocellular carcinoma(HCC),decompensation,and liver-related events.METHODS The PubMed,EMBASE,and Cochrane Library databases were searched up to March 5,2023.Outcomes of interest were assessed by pooled hazard ratios(HRs).The study was registered with PROSPERO(CRD42023405345).RESULTS Six cohort studies representing 3155 patients were included.Compared with patients with undetectable HBV DNA,patients with LLV was associated with increased risk of HCC(HR:2.06,95%CI:1.36-3.13;Q-statistic-P=0.07,I^(2)=51%)regardless of receiving AVT or not(AVT group:HR:3.14;95%CI:1.73-5.69;Qstatistic-P=0.60,I2=0%;un-AVT group:HR:1.73,95%CI:1.09-2.76;Q-statistic-P=0.11,I2=50%).The pooled results showed no statistical association between LLV and decompensation of cirrhosis(HR:2.06,95%CI:0.89-4.76;Q-statistic-P=0.04,I2=69%),and liver-related events(HR:1.84,95%CI:0.92-3.67;Q-statistic-P=0.03,I2=72%),respectively.Grading of Recommendations Assessment,Development and Evaluation assessment indicated moderate certainty for HCC,very low certainty for decompensation of cirrhosis and liver-related clinical events.CONCLUSION LLV in compensated cirrhotic patients is associated with increased risk of HCC,higher tendency for hepatic decompensation and liver-related events.Closer screening of HCC should be conducted in this population.展开更多
Low sperm motility is one of the main causes of male infertility. Cystic fibrosis transmembrane conductance regulator (CFTR, an anion channel protein) is related to the progressive motility of sperm. CFTR disruptor CF...Low sperm motility is one of the main causes of male infertility. Cystic fibrosis transmembrane conductance regulator (CFTR, an anion channel protein) is related to the progressive motility of sperm. CFTR disruptor CFTRinh-172 or forskolin (FSK) in this study were used to treat human sperm separately, and the rates of sperm autophagy and progressive motility, mitochondrial membrane potential (MMP) and ATP concentration, and the expression levels of related factors were detected to explore their relationship. It was showed that sperms treated with CFTRinh-172 or FSK reduced the levels of cAMP, CFTR and PKA, but increased sperm autophagy rate, expression levels of AMPK and LC3B. However, reactive oxygen species content had no significant difference. It was indicated that low level of CFTR performed with cAMP and its downstream effectors such as PKA and AMPK to regulate mitochondrial structure and function, leading to increased autophagy rate and reduced vitality of sperm.展开更多
Considering droplet phenomena at low Mach numbers,large differences in the magnitude of the occurring characteristic waves are presented.As acoustic phenomena often play a minor role in such applications,classical exp...Considering droplet phenomena at low Mach numbers,large differences in the magnitude of the occurring characteristic waves are presented.As acoustic phenomena often play a minor role in such applications,classical explicit schemes which resolve these waves suffer from a very restrictive timestep restriction.In this work,a novel scheme based on a specific level set ghost fluid method and an implicit-explicit(IMEX)flux splitting is proposed to overcome this timestep restriction.A fully implicit narrow band around the sharp phase interface is combined with a splitting of the convective and acoustic phenomena away from the interface.In this part of the domain,the IMEX Runge-Kutta time discretization and the high order discontinuous Galerkin spectral element method are applied to achieve high accuracies in the bulk phases.It is shown that for low Mach numbers a significant gain in computational time can be achieved compared to a fully explicit method.Applica-tions to typical droplet dynamic phenomena validate the proposed method and illustrate its capabilities.展开更多
The low level red light irradiation dose that produced positive response on different cell indexes was selected through experiments.In fibroblast detection model,the low level red light irradiation dose that had posit...The low level red light irradiation dose that produced positive response on different cell indexes was selected through experiments.In fibroblast detection model,the low level red light irradiation dose that had positive response to the four indicators of mitochondrial membrane potential,ATP release,cell migration and collagen synthesis was screened.The experimental results showed that low level red light with a irradiation dose of 2 J/cm^(2) had a positive response to the above four indexes in fibroblast.The test model on fibroblast was later transferred to dermal papilla cells for further experimental verification.The results showed that low level red light with a irradiation dose of 2 J/cm^(2) also had a positive response to the four indicators of dermal papilla cells,namely,mitochondrial membrane potential,ATP release,cell proliferation rate and collagen synthesis.It is proved that the low level red light with a irradiation dose of 2 J/cm^(2) could improve the mitochondrial function,cell migration and collagen synthesis of fibroblast and dermal papilla cell,thus providing energy for cell activities,improving cell repair ability and cell anti-aging ability.展开更多
Objective:To study the predictive value of serum pregenomic RNA(pgRNA)on HBeAg clearance in patients with chronic hepatitis B with low HBeAg levels during pegylated interferon therapy.Methods:Twenty chronic hepatitis ...Objective:To study the predictive value of serum pregenomic RNA(pgRNA)on HBeAg clearance in patients with chronic hepatitis B with low HBeAg levels during pegylated interferon therapy.Methods:Twenty chronic hepatitis B patients with HBeAg positive and quantitative<50S/CO were selected for this study.The subjects underwent pegylated interferon therapy for 48-96 weeks and were followed up in the outpatient clinic after treatment.The patients were then divided into groups based on whether their HbeAg turned negative.The predictive ability of each indicator for HBeAg negative conversion was evaluated in the HBeAg negative group and the HBeAg positive group.Results:The results of logistic regression analysis suggested that pgRNA and HBcrAg were better indicators for predicting the clearance of HBeAg after treatment.Conclusion:For patients with chronic hepatitis B with low HBeAg levels,pgRNA is a good indicator in predicting HBeAg clearance during pegylated interferon therapy.展开更多
A mathematical model of quantum noise having much effect on the low light imaging system is set up. To simulate the quantum noise, the random numbers obeying noise distribution must be formed and are weighted on the...A mathematical model of quantum noise having much effect on the low light imaging system is set up. To simulate the quantum noise, the random numbers obeying noise distribution must be formed and are weighted on the basis of the model created. Three uniform random sequences are built by the linear congruential method, of which two are used to form integer number and decimal fraction parts of the new random sequence respectively and the third to shuffle the new sequence. And then a Gauss sequence is formed out of uniform distribution by a function transforming method. It actualizes the simulation in real time of quantum noise in the low light imaging system, where video flow is extracted in real time, the noise summed up and played back side by side with the original video signs by a simulation software.展开更多
Three-month wind profiles, 260 m PM_1 concentrations [i.e., particulate matter(PM) with an aerodynamic diameter ≤1μm], and carrier-to-noise ratio data at two Beijing sites 55 km apart(urban and suburban) were collec...Three-month wind profiles, 260 m PM_1 concentrations [i.e., particulate matter(PM) with an aerodynamic diameter ≤1μm], and carrier-to-noise ratio data at two Beijing sites 55 km apart(urban and suburban) were collected to analyze the characteristics of low-level nocturnal wind and PM in autumn and winter. Three mountain-plain wind events with wind shear were selected for analysis. The measurements indicated that the maximum wind speeds of the northerly weak low-level jet(LLJ) below 320 m at the suburban site were weaker than those at the urban site, and the LLJ heights and depths at the suburban site were lower than those at the urban site. The nocturnal 140 m mean vertical velocities and the variations in vertical velocity at the urban site were larger than those at the suburban site. A nocturnal breeze with a weak LLJ of ~3 m s^(-1) noticeably offset nocturnal PM transport due to southerly flow and convergence within the northern urban area of Beijing. Characteristics of the nocturnal LLJ, such as start-up time, structure, intensity, and duration, were important factors in determining the decrease in the nocturnal horizontal range and site-based low-level variations in PM.展开更多
The thermal stratification level of low sidewall air supply system in large space was defined. Depending on the experiment of low sidewall air supply in summer 2008,the thermal stratification level was studied by simu...The thermal stratification level of low sidewall air supply system in large space was defined. Depending on the experiment of low sidewall air supply in summer 2008,the thermal stratification level was studied by simulation. Based on the simulation of experiment condition,the air velocity and vertical temperature distribution in a large space were simulated at different air-outlet velocities,and then the thermal stratification level line was obtained. The simulation results well match with the experimental ones and the average relative error is 3.4%. The thermal stratification level is heightened by increasing the air-outlet velocity with low sidewall air supply mode. It is concluded that when air-outlet velocity is 0.29 m/s,which is the experimental case,a uniform thermal environment in the higher occupied zone and a stable stratification level are formed. When the air-outlet velocity is low,such as 0.05 m/s,the thermal stratification level is too low and the air velocity is too small to meet the human thermal comfort in the occupied zone. So,it would be reasonable that the air-outlet velocity may be designed as 0.31 m/s if the height of the occupied zone is 2 m.展开更多
Based on the previous research on the model of rainstorm weather with low-level jet in Xiangtan,using the classification result of radar echo characteristics,the wind profile data provided by new generation of weather...Based on the previous research on the model of rainstorm weather with low-level jet in Xiangtan,using the classification result of radar echo characteristics,the wind profile data provided by new generation of weather radar in Changsha and hourly rainfall data,a thorough study of the heavy rainfall from 2 to 5 July 2016 in Xiangtan was conducted. It was concluded that heavy precipitation had the characteristics of the WPSH pattern of rainstorm with low-level jet at early stage,and then it converted to cold shear jet pattern in latter stage. When low-level southwest jet began to have momentum download,that is to say,there was more than 12 m/s of southwest jet below 1 km,and it rapidly strengthened and expanded downward,it was conducive to the occurrence of short-term rainstorm. The low-level jet would not immediately cause a strong precipitation when it reached the station,with a certain lag. A positive correlation existed between the increase of low-level jet index and precipitation intensity,and low-level jet index could predict the occurrence of heavy rainfall and rain intensity.展开更多
Traumatic brain injury is a major health concern worldwide with massive financial and social impact. Conventional treatments primarily focus on the prevention of further damage to the brain parenchyma, while failing t...Traumatic brain injury is a major health concern worldwide with massive financial and social impact. Conventional treatments primarily focus on the prevention of further damage to the brain parenchyma, while failing to address the already existent symptoms. Previous clinical studies have shown that Low Level Laser Therapy (LLLT) can significantly reduce pain and induce temporary vasodilation in capillaries, which the authors hypothesize can be used to improve the quality of life in TBI patients by treating their current symptoms, which are predominately migraine-like headaches. This case report illustrates the use of LLLT in the treatment of a patient with a TBI and the great clinical success achieved in the reduction of pain, as measured by VAS—achievable within five treatments of 10 minutes in duration.展开更多
We describe an observational study of clinical, virologic and drug resistance profiles in HIV-positive antiretroviral adherent subjects with stable low level viremia (LLV) 50 - 1000 copies/mL for more than 12 months. ...We describe an observational study of clinical, virologic and drug resistance profiles in HIV-positive antiretroviral adherent subjects with stable low level viremia (LLV) 50 - 1000 copies/mL for more than 12 months. Subjects were followed from time of first detectable viral load (VL). In total, 102 episodes of LLV were detected among 80 individuals. The median (mean, range) HIV copy number at genotyping was 250 (486, - 3900) copies/mL after 14 (17.9, 0 - 58) months of LLV. Few patients maintained LLV for the entire 9 years period of observation, with half (52%) experiencing viremic progression following a stable period of LLV either spontaneously or after treatment interruption or failed regimen intensification. In the setting of prolonged periods of sustained LLV, mean duration 22 (range 8 - 106) months, drug resistance (DR) was almost universal. Resistance to ≥1 on-treatment drugs was defined in 97% of specimens and DR to all drugs in the treatment regimen in over half of all patients. Evolution of DR mutations during the period of LLV was observed in 20/28 (71%) subjects with specimens available for follow-up testing. This evolution was associated with viremic progression to levels >1000 copies/mL (p = 0.03). Our data suggest that DR present in patients with LLV is likely to impact long term clinical outcomes, highlighting the importance of optimizing techniques to detect the presence of drug resistant HIV in the setting of LLV and the need for larger prospective studies to assess the emergence of DR in the setting of sustained LLV and the impact of this DR on treatment outcomes.展开更多
Injury to axons close to the neuronal bodies in the mammalian central nervous system causes a large proportion of parenting neurons to degenerate. It is known that optic nerve transection close to the eye in rodents l...Injury to axons close to the neuronal bodies in the mammalian central nervous system causes a large proportion of parenting neurons to degenerate. It is known that optic nerve transection close to the eye in rodents leads to a loss of about half of retinal ganglion cells in 1 week and about 90% in 2 weeks. Using low level laser treatment in the present study, we demonstrated that treatment with helium-neon (660 nm) laser with 15 mW power could delay retinal ganglion cell death after optic nerve axotomy in adult hamsters. The effect was most apparent in the ifrst week with a short period of treatment time (5 minutes) in which 65–66% of retinal ganglion cells survived the optic nerve axotomy whereas 45–47% of retinal ganglion cells did so in optic nerve axotomy controls. We also found that single dose and early commencement of laser irradiation were important in protecting retinal ganglion cells following optic nerve axotomy. These ifndings thus convincingly show that appropriate laser treatment may be neuroprotective to retinal gan-glion cells.展开更多
AIM: To validate the protocol described here to be used in future clinical trials related to the effect of laser therapy on dental pulp. METHODS: Histologically treated samples from eight human healthy premolar teeth ...AIM: To validate the protocol described here to be used in future clinical trials related to the effect of laser therapy on dental pulp. METHODS: Histologically treated samples from eight human healthy premolar teeth obtained from the middle root level were distributed in four groups: group 1(G1) absolute control; group 2(G2) only laser irradiation; group 3(G3) exposed only to orthodontics; and group 4(G4) treated with orthodontics and laser. Laser treatment was performed at 830 nm wavelength, 100 mW(energy 80 J/cm2, 2.2 J), for 22 s in the vestibular surface and 22 s in the palatal surface, 1 mm away from the dental root mucosa. Three staining methods were performed: hematoxylin-eosin(HE), Masson's Trichrome method and Gomori's method.RESULTS: The pulp histology parameters were evaluated and the results classified in to 3 parts: an inflammatory response, soft tissue response(dental pulp) and hard tissue response(dentin and predentin). There was no inflammation(chronic or acute) in any of the evaluated groups. The zones of pulp necrosis were found in one premolar of G3 and in one of G4; in groups G2 and G4 there was higher angiogenesis than in the other two groups. G4 group presented the highest level of vascularization. A reduced nerve density was observed in G3. A G2 specimen showed increased nerve density. A higher rate of calcification was observed in G1 compared to G2. Denticles, either real or false, were observed in G1, G2 and G3. Sclerosis of dentin and focal dentin loss was observed among all the groups. Secondary dentin was present in one sample in G1 and G2. A necrosis zone was found in one sample of G3 and G4. No differences between groups were observed in the odontoblast irregularity layer but the layer was wider in the group treated with laser only. A notable difference was detected in reduction of the cell-free layer between the groups G1 and G4. The findings in pulp tissue favor its adaptative response against dental movement induced by orthodontics. No definitive conclusions may be derived as this is a pilot study. CONCLUSION: The protocol described here was shown to be an effective method to evaluate changes in dental pulp submitted to low level laser in teeth under orthodontic movement.展开更多
This work focuses on how to maintain a high-energy orbit motion of a bistable oscillator when subjected to a low level excitation. An elastic magnifier (EM) positioned between the base and the bistable oscillator is...This work focuses on how to maintain a high-energy orbit motion of a bistable oscillator when subjected to a low level excitation. An elastic magnifier (EM) positioned between the base and the bistable oscillator is used to magnify the base vibration displacement to significantly enhance the output characteristics of the bistable oscillator. The dimensionless electromechanical equations of the bistable oscillator with an EM are derived, and the effects of the mass and stiffness ratios between the EM and the bistable oscillator on the output displacement are studied. It is shown that the jump phenomenon occurs at a lower excitation level with increasing the mass and stiffness ratios. With the comparison of the displacement trajectories and the phase portraits obtained from experiments, it is vMidated that the bistable oscillator with an EM can effectively oscillate in a high-energy orbit and can generate a superior output vibration at a low excitation level as compared with the bistable oscillator without an EM.展开更多
In the storage ring RF system of Shanghai Synchrotron Radiation Facility,the clock distribution and the local oscillator are two parts of the digital low level radio frequency hardware board.In this paper,we designed ...In the storage ring RF system of Shanghai Synchrotron Radiation Facility,the clock distribution and the local oscillator are two parts of the digital low level radio frequency hardware board.In this paper,we designed and produced the clock distribution and the local oscillator board using the AD9858 and AD9510 chips.The results show that the phase noise of the local oscillator signal is lower than 100dBc/Hz with 50 kHz offset.展开更多
In order to understand the activity characteristics of low-level jets in the Nanjing area,statistical analysis and comparative study are carried out on their monthly and diurnal variations,characteristics of their cor...In order to understand the activity characteristics of low-level jets in the Nanjing area,statistical analysis and comparative study are carried out on their monthly and diurnal variations,characteristics of their cores and accompanying weather conditions using wind profile data in 2005-2008 collected by two wind profilers.The results show that low-level jets have significant monthly and diurnal variations.They occur more frequently in spring and summer than in autumn and winter and are more active in early morning and at night,with the maximum wind speed usually occurring at midnight.The central part of the low-level jet occurs mainly at the height of less than 1400 meters,and the enhancement of central speed is beneficial to the appearance of precipitation.Meanwhile,when the low-level jet appears in summer,it helps cause heavy rain.The statistical results of the boundary wind profiler are well consistent with those of the tropospheric wind profiler.Two kinds of wind profilers also have the capability of continuously detecting the development of low-level jets.展开更多
Objective To gain a better understanding of gene expression changes in the brain following microwave exposure in mice. This study hopes to reveal mechanisms contributing to microwave-induced learning and memory dysfun...Objective To gain a better understanding of gene expression changes in the brain following microwave exposure in mice. This study hopes to reveal mechanisms contributing to microwave-induced learning and memory dysfunction. Methods Mice were exposed to whole body 2100 MHz microwaves with specific absorption rates (SARs) of 0.45 W/kg, 1.8 W/kg, and 3.6 W/kg for 1 hour daily for 8 weeks. Differentially expressing genes in the brains were screened using high-density oligonucleotide arrays, with genes showing more significant differences further confirmed by RT-PCR. Results The gene chip results demonstrated that 41 genes (0.45 W/kg group), 29 genes (1.8 W/kg group), and 219 genes (3.6 W/kg group) were differentially expressed. GO analysis revealed that these differentially expressed genes were primarily involved in metabolic processes, cellular metabolic processes, regulation of biological processes, macromolecular metabolic processes, biosynthetic processes, cellular protein metabolic processes, transport, developmental processes, cellular component organization, etc. KEGG pathway analysis showed that these genes are mainly involved in pathways related to ribosome, Alzheimer's disease, Parkinson's disease, long-term potentiation, Huntington's disease, and Neurotrophin signaling. Construction of a protein interaction network identified several important regulatory genes including synbindin (sbdn), Crystallin (CryaB), PPP1CA, Ywhaq, Psap, Psmb1, Pcbp2, etc., which play important roles in the processes of learning and memory. Conclusion Long-term, low-level microwave exposure may inhibit learning and memory by affecting protein and energy metabolic processes and signaling pathways relating to neurological functions or diseases.展开更多
Low-level radio frequency(LLRF)systems stabilize the electromagnetic field in the RF cavities used for beam acceleration in particle accelerators.Reliable,accurate,and precise detection of RF amplitude and phase is pa...Low-level radio frequency(LLRF)systems stabilize the electromagnetic field in the RF cavities used for beam acceleration in particle accelerators.Reliable,accurate,and precise detection of RF amplitude and phase is particularly important to achieve high field stability for pulsed accelerators of free-electron lasers(FEL).The digital LLRF systems employ analog-to-digital converters to sample the frequency down-converted RF signal and use digital demodulation algorithms to calculate the RF amplitude and phase.Different sampling strategies and demodulation algorithms have been developed for these purposes and are introduced in this paper.This article focuses on advanced topics concerning RF detection,including accurate RF transient measurement,wideband RF detection,and RF detection with an asynchronous trigger,local oscillator,or clock.The analysis is based on the SwissFEL measurements,but the algorithms introduced are general for RF signal detection in particle accelerators.展开更多
On the basis of the budget equations for KR and KD, this paper presents the horizontal pattern of budget terms for two kinds of low level jets (LLJ ) with and without heavy rain. The results show that the mechanisms f...On the basis of the budget equations for KR and KD, this paper presents the horizontal pattern of budget terms for two kinds of low level jets (LLJ ) with and without heavy rain. The results show that the mechanisms for generating and maintaining LLJ are different, and especially, the direction of energy conversion is opposite. A positive conversion from KD to KR appears to be a necessary but not sufficient condition in the lower troposphere near the heavy rain area. The intensity and direction of energy conversion depends not only on the relative position of vorticity and divergence field, but also on the vertical profile of the jets directly.展开更多
文摘Background: Improving Water, Sanitation and Hygiene in health care settings is a critical prerequisite for achieving national health goals and Sustainable Development Goals (SDGs). The World Health Organization (WHO) has set a target for each United Nations member state to reach by 2030. Each member state is required to reach by 2022, 2025 and 2030 at least 60%, 80% and 100%, respectively of basic level of service of the five elements which are water, sanitation, hygiene, waste management and environmental cleaning. Methods: This study aimed to evaluate and document the current state of basic water, sanitation, and hygiene services in all lower-level health care facilities in the Dar es Salaam region of Tanzania as of July 2022. A cross-sectional study was conducted in 99 public dispensaries in the Dar es Salaam region’s five councils: Ubungo, Kigamboni, Kinondoni and Temeke Municipalities, and Ilala City. The interviewee form and observational checklists were both digitalized using the Kobo tool software. The respondents were health care facility in-charges or nurse in-charges. Data were downloaded, validated, and imported to Stata version 15 for analysis. Results: The basic WASH level per JMP is far below the target in 2022. Each member state by 2022 is required to reach at least 60% of the basic level of service of each element. We found a low coverage of basic WASH in the 99 dispensaries included in this study. The basic WASH coverage was met in only 10 (10.1%) of the dispensaries, while the remaining 89 (89.9%) dispensaries fall on limited WASH services. Conclusion: This study revealed lower coverage of basic WASH services in dispensaries. An urgent need is required to improve the status of WASH in all the dispensaries and facilitate the provision of quality health care services, patient safety and reduce health care associated infections.
基金Supported by the National Natural Science Foundation of China,No.82070574。
文摘BACKGROUND Whether patients with compensated cirrhosis and low-level viremia(LLV)of hepatitis B should receive antiviral therapy(AVT)is still controversial,and published results are inconsistent.AIM To investigate the link between LLV in compensated cirrhosis and prognosis concerning hepatocellular carcinoma(HCC),decompensation,and liver-related events.METHODS The PubMed,EMBASE,and Cochrane Library databases were searched up to March 5,2023.Outcomes of interest were assessed by pooled hazard ratios(HRs).The study was registered with PROSPERO(CRD42023405345).RESULTS Six cohort studies representing 3155 patients were included.Compared with patients with undetectable HBV DNA,patients with LLV was associated with increased risk of HCC(HR:2.06,95%CI:1.36-3.13;Q-statistic-P=0.07,I^(2)=51%)regardless of receiving AVT or not(AVT group:HR:3.14;95%CI:1.73-5.69;Qstatistic-P=0.60,I2=0%;un-AVT group:HR:1.73,95%CI:1.09-2.76;Q-statistic-P=0.11,I2=50%).The pooled results showed no statistical association between LLV and decompensation of cirrhosis(HR:2.06,95%CI:0.89-4.76;Q-statistic-P=0.04,I2=69%),and liver-related events(HR:1.84,95%CI:0.92-3.67;Q-statistic-P=0.03,I2=72%),respectively.Grading of Recommendations Assessment,Development and Evaluation assessment indicated moderate certainty for HCC,very low certainty for decompensation of cirrhosis and liver-related clinical events.CONCLUSION LLV in compensated cirrhotic patients is associated with increased risk of HCC,higher tendency for hepatic decompensation and liver-related events.Closer screening of HCC should be conducted in this population.
文摘Low sperm motility is one of the main causes of male infertility. Cystic fibrosis transmembrane conductance regulator (CFTR, an anion channel protein) is related to the progressive motility of sperm. CFTR disruptor CFTRinh-172 or forskolin (FSK) in this study were used to treat human sperm separately, and the rates of sperm autophagy and progressive motility, mitochondrial membrane potential (MMP) and ATP concentration, and the expression levels of related factors were detected to explore their relationship. It was showed that sperms treated with CFTRinh-172 or FSK reduced the levels of cAMP, CFTR and PKA, but increased sperm autophagy rate, expression levels of AMPK and LC3B. However, reactive oxygen species content had no significant difference. It was indicated that low level of CFTR performed with cAMP and its downstream effectors such as PKA and AMPK to regulate mitochondrial structure and function, leading to increased autophagy rate and reduced vitality of sperm.
基金support provided by the Deutsche Forschun-gsgemeinschaft(DFG,German Research Foundation)through the project GRK 2160/1“Droplet Interaction Technologies”and through the project no.457811052
文摘Considering droplet phenomena at low Mach numbers,large differences in the magnitude of the occurring characteristic waves are presented.As acoustic phenomena often play a minor role in such applications,classical explicit schemes which resolve these waves suffer from a very restrictive timestep restriction.In this work,a novel scheme based on a specific level set ghost fluid method and an implicit-explicit(IMEX)flux splitting is proposed to overcome this timestep restriction.A fully implicit narrow band around the sharp phase interface is combined with a splitting of the convective and acoustic phenomena away from the interface.In this part of the domain,the IMEX Runge-Kutta time discretization and the high order discontinuous Galerkin spectral element method are applied to achieve high accuracies in the bulk phases.It is shown that for low Mach numbers a significant gain in computational time can be achieved compared to a fully explicit method.Applica-tions to typical droplet dynamic phenomena validate the proposed method and illustrate its capabilities.
文摘The low level red light irradiation dose that produced positive response on different cell indexes was selected through experiments.In fibroblast detection model,the low level red light irradiation dose that had positive response to the four indicators of mitochondrial membrane potential,ATP release,cell migration and collagen synthesis was screened.The experimental results showed that low level red light with a irradiation dose of 2 J/cm^(2) had a positive response to the above four indexes in fibroblast.The test model on fibroblast was later transferred to dermal papilla cells for further experimental verification.The results showed that low level red light with a irradiation dose of 2 J/cm^(2) also had a positive response to the four indicators of dermal papilla cells,namely,mitochondrial membrane potential,ATP release,cell proliferation rate and collagen synthesis.It is proved that the low level red light with a irradiation dose of 2 J/cm^(2) could improve the mitochondrial function,cell migration and collagen synthesis of fibroblast and dermal papilla cell,thus providing energy for cell activities,improving cell repair ability and cell anti-aging ability.
基金the grant from SPPH Incubator Fund for Development of Science and Technology(2021YJY-19)SPPH Foundation for Development of Science and Technology(2021BJ-26)International Science and Technology Cooperation Projects of Shaanxi Province(2022KW-14).
文摘Objective:To study the predictive value of serum pregenomic RNA(pgRNA)on HBeAg clearance in patients with chronic hepatitis B with low HBeAg levels during pegylated interferon therapy.Methods:Twenty chronic hepatitis B patients with HBeAg positive and quantitative<50S/CO were selected for this study.The subjects underwent pegylated interferon therapy for 48-96 weeks and were followed up in the outpatient clinic after treatment.The patients were then divided into groups based on whether their HbeAg turned negative.The predictive ability of each indicator for HBeAg negative conversion was evaluated in the HBeAg negative group and the HBeAg positive group.Results:The results of logistic regression analysis suggested that pgRNA and HBcrAg were better indicators for predicting the clearance of HBeAg after treatment.Conclusion:For patients with chronic hepatitis B with low HBeAg levels,pgRNA is a good indicator in predicting HBeAg clearance during pegylated interferon therapy.
文摘A mathematical model of quantum noise having much effect on the low light imaging system is set up. To simulate the quantum noise, the random numbers obeying noise distribution must be formed and are weighted on the basis of the model created. Three uniform random sequences are built by the linear congruential method, of which two are used to form integer number and decimal fraction parts of the new random sequence respectively and the third to shuffle the new sequence. And then a Gauss sequence is formed out of uniform distribution by a function transforming method. It actualizes the simulation in real time of quantum noise in the low light imaging system, where video flow is extracted in real time, the noise summed up and played back side by side with the original video signs by a simulation software.
基金supported by the National Key R&D Program of China (Grant No.2017YFC0209801)the National Natural Science Foundation of China (Grant Nos.41505091,91544221,41675137,41575124 and 41505116)
文摘Three-month wind profiles, 260 m PM_1 concentrations [i.e., particulate matter(PM) with an aerodynamic diameter ≤1μm], and carrier-to-noise ratio data at two Beijing sites 55 km apart(urban and suburban) were collected to analyze the characteristics of low-level nocturnal wind and PM in autumn and winter. Three mountain-plain wind events with wind shear were selected for analysis. The measurements indicated that the maximum wind speeds of the northerly weak low-level jet(LLJ) below 320 m at the suburban site were weaker than those at the urban site, and the LLJ heights and depths at the suburban site were lower than those at the urban site. The nocturnal 140 m mean vertical velocities and the variations in vertical velocity at the urban site were larger than those at the suburban site. A nocturnal breeze with a weak LLJ of ~3 m s^(-1) noticeably offset nocturnal PM transport due to southerly flow and convergence within the northern urban area of Beijing. Characteristics of the nocturnal LLJ, such as start-up time, structure, intensity, and duration, were important factors in determining the decrease in the nocturnal horizontal range and site-based low-level variations in PM.
基金Project(50478113) supported by the National Natural Science Foundation of ChinaProject(J50502) supported by the Leading Academic Discipline Project of Shanghai Municipal Education Commission,China
文摘The thermal stratification level of low sidewall air supply system in large space was defined. Depending on the experiment of low sidewall air supply in summer 2008,the thermal stratification level was studied by simulation. Based on the simulation of experiment condition,the air velocity and vertical temperature distribution in a large space were simulated at different air-outlet velocities,and then the thermal stratification level line was obtained. The simulation results well match with the experimental ones and the average relative error is 3.4%. The thermal stratification level is heightened by increasing the air-outlet velocity with low sidewall air supply mode. It is concluded that when air-outlet velocity is 0.29 m/s,which is the experimental case,a uniform thermal environment in the higher occupied zone and a stable stratification level are formed. When the air-outlet velocity is low,such as 0.05 m/s,the thermal stratification level is too low and the air velocity is too small to meet the human thermal comfort in the occupied zone. So,it would be reasonable that the air-outlet velocity may be designed as 0.31 m/s if the height of the occupied zone is 2 m.
基金Supported by Forecasters' Special Project of Hunan Meteorological Bureau in 2016(XQKJ16C003)
文摘Based on the previous research on the model of rainstorm weather with low-level jet in Xiangtan,using the classification result of radar echo characteristics,the wind profile data provided by new generation of weather radar in Changsha and hourly rainfall data,a thorough study of the heavy rainfall from 2 to 5 July 2016 in Xiangtan was conducted. It was concluded that heavy precipitation had the characteristics of the WPSH pattern of rainstorm with low-level jet at early stage,and then it converted to cold shear jet pattern in latter stage. When low-level southwest jet began to have momentum download,that is to say,there was more than 12 m/s of southwest jet below 1 km,and it rapidly strengthened and expanded downward,it was conducive to the occurrence of short-term rainstorm. The low-level jet would not immediately cause a strong precipitation when it reached the station,with a certain lag. A positive correlation existed between the increase of low-level jet index and precipitation intensity,and low-level jet index could predict the occurrence of heavy rainfall and rain intensity.
文摘Traumatic brain injury is a major health concern worldwide with massive financial and social impact. Conventional treatments primarily focus on the prevention of further damage to the brain parenchyma, while failing to address the already existent symptoms. Previous clinical studies have shown that Low Level Laser Therapy (LLLT) can significantly reduce pain and induce temporary vasodilation in capillaries, which the authors hypothesize can be used to improve the quality of life in TBI patients by treating their current symptoms, which are predominately migraine-like headaches. This case report illustrates the use of LLLT in the treatment of a patient with a TBI and the great clinical success achieved in the reduction of pain, as measured by VAS—achievable within five treatments of 10 minutes in duration.
文摘We describe an observational study of clinical, virologic and drug resistance profiles in HIV-positive antiretroviral adherent subjects with stable low level viremia (LLV) 50 - 1000 copies/mL for more than 12 months. Subjects were followed from time of first detectable viral load (VL). In total, 102 episodes of LLV were detected among 80 individuals. The median (mean, range) HIV copy number at genotyping was 250 (486, - 3900) copies/mL after 14 (17.9, 0 - 58) months of LLV. Few patients maintained LLV for the entire 9 years period of observation, with half (52%) experiencing viremic progression following a stable period of LLV either spontaneously or after treatment interruption or failed regimen intensification. In the setting of prolonged periods of sustained LLV, mean duration 22 (range 8 - 106) months, drug resistance (DR) was almost universal. Resistance to ≥1 on-treatment drugs was defined in 97% of specimens and DR to all drugs in the treatment regimen in over half of all patients. Evolution of DR mutations during the period of LLV was observed in 20/28 (71%) subjects with specimens available for follow-up testing. This evolution was associated with viremic progression to levels >1000 copies/mL (p = 0.03). Our data suggest that DR present in patients with LLV is likely to impact long term clinical outcomes, highlighting the importance of optimizing techniques to detect the presence of drug resistant HIV in the setting of LLV and the need for larger prospective studies to assess the emergence of DR in the setting of sustained LLV and the impact of this DR on treatment outcomes.
基金supported by Key Basic Research Project of China(973 Program),No.2011CB707501Fundamental Research Funds for The Central Universities,No.21609101
文摘Injury to axons close to the neuronal bodies in the mammalian central nervous system causes a large proportion of parenting neurons to degenerate. It is known that optic nerve transection close to the eye in rodents leads to a loss of about half of retinal ganglion cells in 1 week and about 90% in 2 weeks. Using low level laser treatment in the present study, we demonstrated that treatment with helium-neon (660 nm) laser with 15 mW power could delay retinal ganglion cell death after optic nerve axotomy in adult hamsters. The effect was most apparent in the ifrst week with a short period of treatment time (5 minutes) in which 65–66% of retinal ganglion cells survived the optic nerve axotomy whereas 45–47% of retinal ganglion cells did so in optic nerve axotomy controls. We also found that single dose and early commencement of laser irradiation were important in protecting retinal ganglion cells following optic nerve axotomy. These ifndings thus convincingly show that appropriate laser treatment may be neuroprotective to retinal gan-glion cells.
文摘AIM: To validate the protocol described here to be used in future clinical trials related to the effect of laser therapy on dental pulp. METHODS: Histologically treated samples from eight human healthy premolar teeth obtained from the middle root level were distributed in four groups: group 1(G1) absolute control; group 2(G2) only laser irradiation; group 3(G3) exposed only to orthodontics; and group 4(G4) treated with orthodontics and laser. Laser treatment was performed at 830 nm wavelength, 100 mW(energy 80 J/cm2, 2.2 J), for 22 s in the vestibular surface and 22 s in the palatal surface, 1 mm away from the dental root mucosa. Three staining methods were performed: hematoxylin-eosin(HE), Masson's Trichrome method and Gomori's method.RESULTS: The pulp histology parameters were evaluated and the results classified in to 3 parts: an inflammatory response, soft tissue response(dental pulp) and hard tissue response(dentin and predentin). There was no inflammation(chronic or acute) in any of the evaluated groups. The zones of pulp necrosis were found in one premolar of G3 and in one of G4; in groups G2 and G4 there was higher angiogenesis than in the other two groups. G4 group presented the highest level of vascularization. A reduced nerve density was observed in G3. A G2 specimen showed increased nerve density. A higher rate of calcification was observed in G1 compared to G2. Denticles, either real or false, were observed in G1, G2 and G3. Sclerosis of dentin and focal dentin loss was observed among all the groups. Secondary dentin was present in one sample in G1 and G2. A necrosis zone was found in one sample of G3 and G4. No differences between groups were observed in the odontoblast irregularity layer but the layer was wider in the group treated with laser only. A notable difference was detected in reduction of the cell-free layer between the groups G1 and G4. The findings in pulp tissue favor its adaptative response against dental movement induced by orthodontics. No definitive conclusions may be derived as this is a pilot study. CONCLUSION: The protocol described here was shown to be an effective method to evaluate changes in dental pulp submitted to low level laser in teeth under orthodontic movement.
基金Supported by the National Natural Science Foundation of China under Grant No 51277165the Natural Science Foundation of Zhejiang Province under Grant No LY15F10001
文摘This work focuses on how to maintain a high-energy orbit motion of a bistable oscillator when subjected to a low level excitation. An elastic magnifier (EM) positioned between the base and the bistable oscillator is used to magnify the base vibration displacement to significantly enhance the output characteristics of the bistable oscillator. The dimensionless electromechanical equations of the bistable oscillator with an EM are derived, and the effects of the mass and stiffness ratios between the EM and the bistable oscillator on the output displacement are studied. It is shown that the jump phenomenon occurs at a lower excitation level with increasing the mass and stiffness ratios. With the comparison of the displacement trajectories and the phase portraits obtained from experiments, it is vMidated that the bistable oscillator with an EM can effectively oscillate in a high-energy orbit and can generate a superior output vibration at a low excitation level as compared with the bistable oscillator without an EM.
基金Supported by Shanghai Synchrotron Radiation Facility
文摘In the storage ring RF system of Shanghai Synchrotron Radiation Facility,the clock distribution and the local oscillator are two parts of the digital low level radio frequency hardware board.In this paper,we designed and produced the clock distribution and the local oscillator board using the AD9858 and AD9510 chips.The results show that the phase noise of the local oscillator signal is lower than 100dBc/Hz with 50 kHz offset.
基金Open Research Foundation for Radar Meteorology and Severe Weather in Nanjing(BJG201203)Research Fund for Fundamental Theories in Institute of Meteorology and oceanography,PLA University of Science and Technology+1 种基金National Natural Science Foundation of China(41005018)Young Scientists Foundation(41105023)
文摘In order to understand the activity characteristics of low-level jets in the Nanjing area,statistical analysis and comparative study are carried out on their monthly and diurnal variations,characteristics of their cores and accompanying weather conditions using wind profile data in 2005-2008 collected by two wind profilers.The results show that low-level jets have significant monthly and diurnal variations.They occur more frequently in spring and summer than in autumn and winter and are more active in early morning and at night,with the maximum wind speed usually occurring at midnight.The central part of the low-level jet occurs mainly at the height of less than 1400 meters,and the enhancement of central speed is beneficial to the appearance of precipitation.Meanwhile,when the low-level jet appears in summer,it helps cause heavy rain.The statistical results of the boundary wind profiler are well consistent with those of the tropospheric wind profiler.Two kinds of wind profilers also have the capability of continuously detecting the development of low-level jets.
基金supported by the Foundation of Astronaut Research and Training Center of China(No.SN 02-3)
文摘Objective To gain a better understanding of gene expression changes in the brain following microwave exposure in mice. This study hopes to reveal mechanisms contributing to microwave-induced learning and memory dysfunction. Methods Mice were exposed to whole body 2100 MHz microwaves with specific absorption rates (SARs) of 0.45 W/kg, 1.8 W/kg, and 3.6 W/kg for 1 hour daily for 8 weeks. Differentially expressing genes in the brains were screened using high-density oligonucleotide arrays, with genes showing more significant differences further confirmed by RT-PCR. Results The gene chip results demonstrated that 41 genes (0.45 W/kg group), 29 genes (1.8 W/kg group), and 219 genes (3.6 W/kg group) were differentially expressed. GO analysis revealed that these differentially expressed genes were primarily involved in metabolic processes, cellular metabolic processes, regulation of biological processes, macromolecular metabolic processes, biosynthetic processes, cellular protein metabolic processes, transport, developmental processes, cellular component organization, etc. KEGG pathway analysis showed that these genes are mainly involved in pathways related to ribosome, Alzheimer's disease, Parkinson's disease, long-term potentiation, Huntington's disease, and Neurotrophin signaling. Construction of a protein interaction network identified several important regulatory genes including synbindin (sbdn), Crystallin (CryaB), PPP1CA, Ywhaq, Psap, Psmb1, Pcbp2, etc., which play important roles in the processes of learning and memory. Conclusion Long-term, low-level microwave exposure may inhibit learning and memory by affecting protein and energy metabolic processes and signaling pathways relating to neurological functions or diseases.
文摘Low-level radio frequency(LLRF)systems stabilize the electromagnetic field in the RF cavities used for beam acceleration in particle accelerators.Reliable,accurate,and precise detection of RF amplitude and phase is particularly important to achieve high field stability for pulsed accelerators of free-electron lasers(FEL).The digital LLRF systems employ analog-to-digital converters to sample the frequency down-converted RF signal and use digital demodulation algorithms to calculate the RF amplitude and phase.Different sampling strategies and demodulation algorithms have been developed for these purposes and are introduced in this paper.This article focuses on advanced topics concerning RF detection,including accurate RF transient measurement,wideband RF detection,and RF detection with an asynchronous trigger,local oscillator,or clock.The analysis is based on the SwissFEL measurements,but the algorithms introduced are general for RF signal detection in particle accelerators.
文摘On the basis of the budget equations for KR and KD, this paper presents the horizontal pattern of budget terms for two kinds of low level jets (LLJ ) with and without heavy rain. The results show that the mechanisms for generating and maintaining LLJ are different, and especially, the direction of energy conversion is opposite. A positive conversion from KD to KR appears to be a necessary but not sufficient condition in the lower troposphere near the heavy rain area. The intensity and direction of energy conversion depends not only on the relative position of vorticity and divergence field, but also on the vertical profile of the jets directly.