•Migration phenomenon of TE load resistance for PV-TE was indicated.•The model of the PV-TE was built and verified.•PV-TE based on two types of PV cells were analyzed.•The load resistances in ...different ambient conditions were compared.
Combing PV with Thermoelectric (TE) would be dominant because it can employ the solar fully spectrum to produce electricity. But the TE efficiency is significantly lower than PV efficiency and the coupling effect between them will limit the performance of PV and TE. The analyze and comparison on the different characteristics among the hybrid module, the PV alone and TE alone is significant to obtain the highest the electrical efficiency. In this paper, the attention was paid to the inconsistent phenomenon of thermoelectric load resistance for photovoltaic–thermoelectric modules. The model of PV-TE was built and verified based on two types of PV cells. The load resistance of TE for the maximum power output was also analyzed under different working conditions for the TE alone, TE in the PV-TE and PV-TE. The results showed that the load resistance of TE for the maximum power output of the TE alone, TE in the PV-TE and PV-TE are all different. For example, the PV-TE module based on the c-Si cell attains its peak value at the load electrical resistance of TE of 0.75 Ω, while the internal electrical resistance of the TE is 0.47 Ω. The PV-TE module based on the GaAs cell shows a maximum efficiency of PV-TE with a load resistance of approximately 1.6 Ω, while the internal electrical resistance of the TE is 2.0 Ω. Referring to the load resistance of TE alone is not suitable for PV-TE maximum power output. In addition, the TE maximum power output does not correspond to the PV-TE maximum power output since the TE load resistances in these two conditions are also different. The study will provide the reference for attaining the correct load resistance for the actual maximum power output of PV-TE module.
To investigate the association of pregnancy weight gain on gut microbiota in pregnant women and newborns.
Pregnant women who had regular antenatal check-ups and were hospitalised for delivery at ...Shanxi Maternal and Child Health Hospital from September 2020 to December 2020 were selected as the study subjects. They were divided into the normal pre-pregnancy weight-normal pregnancy weight gain group (N-NG group), the normal pregnancy weight-excessive pregnancy weight gain group (N-EG group), the pre-pregnancy overweight/obese-normal pregnancy weight gain group (O-NG group) and the pre-pregnancy overweight/obese-excessive pregnancy weight gain group (O-EG group). Faecal samples of the pregnant women before delivery (37-41
weeks of gestation) and the first meconium samples of their newborns were collected, sequenced for 16S rRNA gut microbiota and analysed. The results of different gut microbiota were compared separately. χ2 test, a one-way analysis of variance or the rank sum test were performed according to data type and distribution. The differences in the Alpha diversity between the groups were analysed using the Kruskal-Wallis rank sum test. The differences in the Beta diversity between the groups were analysed using the Adonis method.
A total of 126 pre-delivery faecal samples from pregnant women and the first faecal samples from their newborns were collected. Seven species with significant abundance differences between the maternal O-NG and N-EG groups and 27 species with significant abundance differences in the newborns were analysed by LEfSe. In the Alpha diversity analysis, the differences in the maternal observed species index and the Chao1 index were statistically significant (p < 0.05) when compared between the groups (O-EG group versus the O-NG group, N-EG group and N-NG group), and the differences in the Shannon index and Simpson index were not statistically significant (p > 0.05) when compared between the groups. The neonatal observed species index, Chao1 index, Shannon index and Simpson index showed statistically significant differences in the comparison between the N-EG and O-EG groups (p < 0.05). In the Beta diversity analysis, the maternal samples did not differ Significantly between the four groups (p > 0.05), while the neonatal samples differed Significantly between the N-EG and N-NG, O-NG, and O-EG groups (p < 0.05).
Pregnancy weight gain affects the composition and abundance of maternal and neonatal gut microbiota species as well as the diversity of neonatal gut microbiota.
Introduction
Aluminum (Al)-activated malate transporters (ALMTs) play an important role in the response to Al toxicity, maintenance of ion homeostasis balance, mineral nutrient distribution, and ...fruit quality development in plants. However, the function of the
StALMT
gene family in potato remains unknown.
Methods and results
In this study, 14
StALMT
genes were identified from the potato genome, unevenly distributed on seven different chromosomes. Collinearity and synteny analyses of
ALMT
genes showed that potatoes had 6 and 22 orthologous gene pairs with Arabidopsis and tomatoes, respectively, and more than one syntenic gene pair was identified for some
StALMT
gene family members. Real-time quantitative polymerase chain reaction (qPCR) results showed differential expression levels of
StALMT
gene family members in different tissues of the potato. Interestingly,
StALMT1
,
StALMT6
,
StALMT8
,
StALMT10
, and
StALMT12
had higher expression in the root of the potato cultivar Qingshu No. 9. After being subjected to Al
3+
stress for 24 h, the expression of
StALMT6
and
StALMT10
in roots was evidently increased, displaying their decisive role in Al
3+
toxicity.
Discussion
In addition, overexpression of
StALMT6
and
StALMT10
in Arabidopsis enhanced its tolerance to Al toxicity. These results indicate that
StALMT6
and
StALMT10
impart Al
3+
resistance in the potato, establishing the foundation for further studies of the biological functions of these genes.
As the basis of image processing, single image deraining has always been a significant and challenging issue. Due to the lack of real rainy images and corresponding clean images, most deraining ...networks are trained by synthetic datasets, which makes the output images unsatisfactory in real applications. Besides, note that a heavy rainfall is typically accompanied with some fog. Although some deraining networks have been proposed to remove the rain streaks in the rainy images, the output images may still be blurred due to the accompanied fog. In this paper, these problems existing in single image deraining is comprehensively considered, and propose a Cycle‐Derain network based on an unsupervised attention‐guided mechanism. Specifically, the Cycle‐Derain network takes advantage of generative adversarial networks with two mappings and the cycle consistency loss to train both unpaired rainy images and rain‐free images. Moreover, it introduces an unsupervised attention‐guided mechanism and exploits the loop‐search positioning algorithm to deal with the details of rain and fog in images. Extensive experiments have been carried out, and the results show that the proposed Cycle‐Derain network is preferable compared with other deraining networks, especially in term of rainy image restoration.
Hepatitis B virus-related acute-on-chronic liver failure (HBV-ACLF) is a rare and severe form of end-stage liver disease with high mortality; gut microbes are strongly associated with the development ...of this severe liver disease but the exact association is unclear. Artificial liver support systems (ALSS) are clinically important in prolonging the waiting time for liver transplantation and in aiding drug therapy to achieve remission. The aim of this study was to investigate the effect of ALSS on the abundance and diversity of microorganisms in the gut of HBV-ACLF patients. In this study, 109 stool samples were collected from patients with hepatitis B virus-associated acute chronic liver failure (HBV-ACLF) for 16S rRNA sequencing. Among them, 44 samples were from patients treated with ALSS therapy as an adjunct to standard medical treatment (SMT) and 65 were from patients receiving SMT only. Analysis of the sequencing results suggested that there were significant differences in the abundance and diversity of gut microbiota between the with-ALSS and without-ALSS groups (p < 0.05). The operational taxonomic units and Shannon indexes indicated that the diversity and abundance of the gut microbiome, while decreasing after the first ALSS treatment, gradually increased after an increase in the number of ALSS therapies. The overall proportion of HBV-ACLF patients with coinfection was 27.59%; the coinfection can reduce the abundance of the Bacteroidetes phylum in the microbiome significantly whereas Proteobacteria were highly enriched. After ALSS therapy, HBV-ACLF patients had a decrease in potentially harmful bacteria, an increase in potentially beneficial bacteria, an increase in the diversity of the intestinal microbiota, and the intestinal microecological disorders were corrected to a certain extent. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), and total bilirubin (TBIL) levels, as well as the international normalized ratio (INR), showed a decreasing trend whereas plasminogen activity (PTA) increased and the condition of patients with HBV-ACLF progressed in a favorable direction. In addition, the abundance of Blautia and Coprococcus was negatively correlated with TBIL and INR, positively correlated with PTA, and positively correlated with disease recovery. Our study shows that ALSS can alter the composition of the gut microbiota and have an ameliorating effect on the gut microecological imbalance in HBV-ACLF patients. It is worth mentioning that Blautia and Coprococcus may have great potential as biomarkers.
Optimal management for congenitally corrected transposition of the great arteries (ccTGA) is controversial. We applied different surgical strategies based on individual variations in our ...single-centered practice over 10 years, aming to describe the mid-term results.
From January 2008 to June 2021, 90 patients with ccTGA were reviewed and grouped by three different surgical strategies: 41 cases with biventricular correction as biventricular group, 11 cases with 1.5 ventricular correction as 1.5 ventricular group, and 38 cases with Fontan palliation as univentricular group. The mean age at primary surgery was 41.4 ± 22.7 months. Patients were followed for mortality, complications, reoperation, cardiac function, and valve status.
The median follow-up period was 5.1 years (range, 1.5-12.5 years). The overall 10-year survival and freedom from reoperation rate was 86.7 and 82.4%, respectively. There were 3 early deaths and 3 mid-term deaths in the biventricular group, while 2 early deaths and 1 mid-term deaths were reported in the univentricular group. Although 1.5 ventricular group presented no death and the fewest complications, we still found similar mortality (
= 0.340) and morbidity (
= 0.670) among the three groups. The bypass time, aortic-clamp time, and ICU stay length were the longest in the biventricular group, followed by the 1.5 ventricular group (
< 0.001). However, in mid-term follow-up, biventricular and 1.5 ventricular groups both showed excellent cardiac function and obvious improvement of tricuspid regurgitation (
= 0.008 and
= 0.051, respectively). Fontan palliation provided acceptable mid-term outcomes as well, despite a lower ejection fraction.
Satisfactory mid-term outcomes could be achieved for highly selected ccTGA patients using the whole spectrum of surgical techniques. Moreover, 1.5 ventricular correction, as a new emerging technique in recent years, might hold great promise in future practice.
A novel photovoltaic/thermal (PV/T) system is designed, which combines Fresnel lens (LF) for linear concentrating, micro-channel heat pipe (MCHP) and thermoelectric generators (TEG) to achieve high ...electrical and thermal output. Aerogel possesses the characteristic of good heat preservation and thermal insulation, thus, applying transparent aerogel glazing to the LF-PV/T-MCHP-TEG system is proposed, to investigate the effects of the different thicknesses of aerogel on performance and compare the system with the no-aerogel system. The results show that adding aerogel enhanced the thermal performance and TEG's performance. The thermal efficiency of the system with 3 cm aerogel was 25.0% under 800 W/m2 irradiation, 3 concentration ratio, 18 °C ambient temperature, and 15 °C initial water temperature, while that of the no-aerogel system was 23.4%. Besides, using aerogel increased the power of TEG by 6 kJ. Nevertheless, the electrical efficiency of PV and overall efficiency of the LFPV/T-MCHP-TEG system with aerogel were 1.8% and 3.0% lower than those of the no-aerogel system under the same conditions. Therefore, there had to be a trade-off between the benefits of better thermal performance and better electrical performance. Furthermore, the influence of TEG modules, solar irradiation, concentration ratios, initial water temperature, and ambient temperature was also discussed.
•A novel PV/T system combined with Fresnel lens, MCHP, and TEG is proposed.•The LFPV/T-MCHP-TEG system with aerogel is compared with that without aerogel.•The system with aerogel has enhanced thermal performance and TEG's performance.•The system without aerogel has great electrical and comprehensive performance.•The impact of different parameters is discussed.
The main problem of concentrated photovoltaics is the high temperature caused by high radiance, which deteriorates the electrical efficiency and service life of photovoltaic cells. Most concentrated ...photovoltaics are assembled into the photovoltaic/thermal systems and cooled by water. However, if concentrating photovoltaics is combined with an evaporator in a direct-expansion solar-assisted heat pump, the photovoltaic damages (reduced life span and conversion efficiency of photovoltaic cells) caused by the high temperature in concentrators will be much better alleviated. But at present, there is little research on the combination of concentrating photovoltaic and direct-expansion solar-assisted heat pump. To enrich the relevant content and explore the optimal concentrating method combined with heat pumps, three hybrid heat pumps with different concentrating evaporators are proposed and investigated. Results indicate that in the photovoltaic heat pump system based on Fresnel concentrator, photovoltaic heat pump system based on compound parabolic concentrator, and the photovoltaic heat pump system based on 3-D crossed compound parabolic concentrator, the electrical efficiency could achieve 30.31%, 15.37%, and 11.66% under 300 W/m2. The coefficient of performance (considering both electricity and heat) could reach 7.65, 5.67, and 5.45 under 800 W/m2, meanwhile, the 29.87%, 16.25%, and 13.66% exergy efficiency can be obtained under the same irradiation. Therefore, the photovoltaic heat pump system based on Fresnel concentrator has the best capacity, followed by the system based on compound parabolic concentrator and 3-D crossed compound parabolic concentrator. Besides, in the FPV-SAHP system, two concentration ratios are designed and discussed. And the effect of ambient temperature, water temperature, as well as solar irradiance on the systems is also explored.
•Compound parabolic concentrator/photovoltaic/fins evaporator is firstly proposed.•The structure is more compact and the pipeline is more simple.•The novel system could make full use of solar and air ...energy in a limited space.•The novel hybrid system is superior to traditional heat pumps.•The exergy efficiency of the novel system is the highest under 200 W/m2 and above.
The evaporator of a traditional photovoltaic solar-assisted heat pump generally covers a large area to meet the heating demand and the performance is poor under low or no irradiation. Many scholars connected an additional finned-tube evaporator in series or parallel to solve the problem, adding additional pipelines. Besides, the heat collection of the plate photovoltaic is still not improved. Thus, a novel direct-expansion solar-assisted heat pump with a hybrid compound parabolic concentrator/photovoltaic/fin evaporator (CPC/PV/fin-SAHP) is proposed in this paper. The newly established system can make full use of solar and air energy in a limited space to achieve a much higher unit output. The mathematical model is established and validated in MATLAB. The investigation on the impact of water temperature, wind speed, irradiation, as well as ambient temperature has been completed. Additionally, a comparison among the novel hybrid heat pump, traditional air-source heat pump, and photovoltaic heat pump has been conducted. Results show that the irradiation and the wind speed are beneficial for the coefficient of performance, but the water temperature is not. When irradiation is 200 W/m2 and above, the novel system is the best in coefficient of performance, total output, and exergy efficiency. Even without irradiation, the coefficient of performance of the novel system could be 4.08 while that of the traditional photovoltaic heat pump is only 1.69. Thus, the proposed system can greatly improve the performance of traditional heat pumps, inspiring the design of high-efficient heat pumps with limited space.
This study presents a detailed performance analysis of a novel concentrated system which consists of a photovoltaic/thermal (PV/T) module with phase change material (PCM) and a solar thermal (ST) ...collector with thermoelectric generators (TEG) connected in series. While considerable electrical energy is acquisitive, enhanced high-temperature thermal energy is also achieved. In this system, the PV/T module generates both photoelectric power generation and low-temperature thermal energy, and the secondary heated water and the secondary thermoelectric output are obtained through the ST module and TEG on ST. Theoretical investigations find that, the system of the PV/T module and the ST module in series (PV/T-ST) performs well in terms of thermal performance and comprehensive performance. During the all-day operation, compared with the PV/T-PV/T system, the final temperature of the water tank in the PV/T-ST system is about 5 °C higher. Also, the electrical efficiency and the thermal efficiency are 10.65% and 65.22% respectively at 12:30 when using the 1.1-m2 Fresnel lens. Where, TEG converts some thermal energy into electrical energy, increasing the amount of high-grade energy of the system by about 321.53 kJ in the daytime. Additionally, the discussion from different perspectives on the impact of different parameters is also carried out.
•A novel concentrated system that connects PV/T and ST in series is proposed.•Both electricity and low-temperature heat can be generated by PV/T.•Reheated water and secondary electrical output are achieved through ST with TEG.•PCM placed in PV/T absorbs heat in the daytime to reduce the temperature of PV.•The discussion on the impact of different parameters is carried out.
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