Numerous biopolymer-based functional composites have been developed for medical applications. Poly(glutamic acid) (PGA) is an amino acid biopolymer that has recently attracted attention due to its ...biocompatibility, non-immunogenicity, and biodegradability. PGA and its composites have been studied to improve their function as medical materials. This review briefly introduces chemically and microbiologically synthesized PGA. In addition, this article provides general and advanced preparation methods for various PGA-based composites, including hydrogels, nanofibers, monoliths, and nanoparticles. Furthermore, it covers recent advances in PGA-based functional composites for medical applications, such as active antimicrobial materials as well as the use of PGA composites for vaccine adjuvants, cancer therapy, medical devices, and tissue regeneration. Anticancer agent delivery and cancer immunotherapy are included in the PGA-based cancer therapy system section. Barrier membranes and stent applications are summarized within the medical devices section. Furthermore, various tissue regeneration topics are introduced, including applications in wound healing, as well as the tissue-specific regeneration of bone, cartilage, intervertebral discs, corneas, kidneys, and neurons. In summary, this is an overview of the various challenges of using PGA and the scope of emerging research.
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The “short‐circuit effect” in the fire‐through Ag metallization of crystalline Si (c‐Si) solar cells refers to the poor contact formation caused by an electrical short between the Ag gridline and ...underlying Si emitter during contact firing. This study employs two different Ag pastes containing PbO‐ and TeO2‐based glass frits to investigate the dependence of the short‐circuit effect on the length and pattern of the Ag finger lines. The results show that regardless of the employed glass frits, the short‐circuit effect is mitigated even near the short spot and gradually attenuated along the finger line away from the spot as the Ag finger line extends radially longer than the critical length (>35 mm). We demonstrate that this attenuation is independent of the finger line width and predominantly attributed to the ohmic drop of the electrode potential along the Si substrate. The results also show that, regardless of the glass frits, the contact quality is strongly correlated with the density of the Ag crystallites that are formed on the Si emitter surface. The 6‐in full‐cell tests indicate that the isolation of the short spots by segmenting the Ag finger lines does not necessarily result in the mitigation of the short‐circuit effect. We suggest that the reduction of Ag+ on the Si emitter surface should be the key process that must be controlled to achieve high‐quality contacts during contact firing, providing further insights into the electrochemical characteristics of contact firing reactions for the future development of Ag pastes.
The electrochemical nature of the contact firing reactions is studied by short‐circuiting the Ag fingers to the underlying Si emitter. The short‐circuit effect is gradually attenuated along the finger line away from the short‐spot owing to the ohmic drop of the electrode potential along the Si substrate. The contact quality is strongly correlated to the Ag crystallites formed on the emitter surface. The 6‐in full‐cell tests demonstrate that the segmentation of Ag fingers does not necessarily mitigate the short‐circuit effect.
Synthetic nanoparticles are extensively utilized in various biomedical engineering fields because of their unique physicochemical properties. However, their exogenous characteristics result in ...synthetic nanosystem invaders that easily induce the passive immune clearance mechanism, thereby increasing the retention effect caused by reticuloendothelial system (RES), resulting in low therapeutic efficacy and toxic effects. Recently, a cell membrane cloaking has been emerging technique as a novel interfacing approach from the biological/immunological perspective. This has been considered as useful technique for improving the performance of synthetic nanocarriers in vivo. By cell membrane cloaking, nanoparticles acquire the biological functions of natural cell membranes due to the presence of membrane-anchored proteins, antigens, and immunological moieties as well as physicochemical property of natural cell membrane. Due to cell membrane cloaking, the derived biological properties and functions of nanoparticles such as their immunosuppressive capability, long circulation time, and disease targeting ability have enhanced their future potential in biomedicine. Here, we review the cell membrane-cloaked nanosystems, highlight their novelty, introduce the preparation and characterization methods with relevant biomedical applications, and describe the prospects for using this novel biomimetic system that was developed from a combination of cell membranes and synthetic nanomaterials.
Cold atmospheric plasma (plasma) has emerged as a novel tool for a cancer treatment option, having been successfully applied to a few types of cancer cells, as well as tissues. However, to date, no ...studies have been performed to examine the effect of plasma on epigenetic alterations, including CpG methylation. In this study, the effects of plasma on DNA methylation changes in breast cancer cells were examined by treating cultured MCF-7 and MDA-MB-231 cells, representing estrogen-positive and estrogen-negative cancer cells, respectively, with plasma. A pyrosequencing analysis of Alu indicated that a specific CpG site was induced to be hypomethylated from 23.4 to 20.3% (p < 0.05) by plasma treatment in the estrogen-negative MDA-MB-231 cells only. A genome-wide methylation analysis identified "cellular movement, connective tissue development and function, tissue development" and "cell-to-cell signaling and interaction, cell death and survival, cellular development" as the top networks. Of the two cell types, the MDA-MB-231 cells underwent a higher rate of apoptosis and a decreased proliferation rate upon plasma treatment. Taken together, these results indicate that plasma induces epigenetic and cellular changes in a cell type-specific manner, suggesting that a careful screening of target cells and tissues is necessary for the potential application of plasma as a cancer treatment option.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Hepatobiliary infections are common in the emergency department (ED), and the mortality rate for this condition is high. A suitable bacteremia prediction model would support prompt identification of ...bacteremia and appropriate management of hepatobiliary infections in the ED. Therefore, we attempted to produce a bacteremia prediction model with both internal and external validation for hepatobiliary infections in the ED.
Patients with hepatobiliary infection were extracted from retrospective cohort databases of two tertiary hospitals from January 2018 to December 2019 and from January 2016 to December 2019, respectively. Independent risk factors were determined using multivariable logistic regression in a developmental cohort. We assigned a weighted value to predictive factors and developed a prediction model, which was validated both internally and externally. We assessed discrimination using the area under the receiver operating characteristics curve (AUC).
One hospital cohort of 1568 patients was randomly divided into a developmental group of 927 patients (60%) and an internal validation group of 641 patients (40%), and 736 people from the other hospital cohort were used for external validation. Bacteremia rates were 20.5%, 18.1%, and 23.1% in the developmental, internal, and external validation cohorts, respectively. Nine significant factors were used for predicting bacteremia, including age, three vital signs, and five laboratory tests. After applying our bacteremia prediction rule to the validation cohort, 56.5% and 53.8% of the internal and external validation groups were classified as low-risk bacteremia groups (bacteremia rates: 8.6% and 13.9%, respectively). The AUCs were 0.727 (95% confidence interval CI: 0.686–0.767), 0.730 (95% CI: 0.679–0.781), and 0.715 (95% CI: 0.672–0.758) for the developmental, internal, and external validation cohorts, respectively. The sensitivity and specificity for internal validation/external validation was 73.2%/67.6% and 63.0%/60.2%, respectively.
A bacteremia prediction model for hepatobiliary infection might be useful to predict the risk of bacteremia. It might also reduce the need for blood culture in low-risk patients.
Background
Some researchers have reported that applying compression closer to the maximum diameter of the left ventricle (Point_max.LV) is associated with worse clinical outcomes, challenging its ...traditional position as optimum compression point (Point_optimum). By locating the mid‐sternum (the actual compression site) in terms of Point_max.LV and its right ventricular equivalent (Point_max.RV), we aimed to determine its optimum horizontal position associated with increased chances of return of spontaneous circulation (ROSC).
Methods
A retrospective, cross‐sectional study was performed at a university hospital from 2014 to 2019 on non‐traumatic out‐of‐hospital cardiac arrest (OHCA) victims who underwent chest computed tomography. On absolute x‐axis, we designated the x‐coordinate of the mid‐sternum (x_mid‐sternum) as 0 and leftward direction as positive. Re‐defining the x‐coordinate of Point_max.RV and Point_max.LV as 0 and 1 interventricular unit (IVU), respectively, we could convert x_mid‐sternum to “−x_max.RV/(x_max.LV − x_max.RV) (IVU).” Using multiple logistic regression analysis, we investigated whether this converted x_mid‐sternum was associated with clinical outcomes, adjusting core elements of the Utstein template.
Results
Among 887 non‐traumatic OHCA victims, 124 64.4 ± 16.7 years, 43 women (34.7%) were enrolled. Of these, 80 (64.5%) exhibited ROSC. X_mid‐sternum ranging from −1.71 to 0.58 (−0.36 ± 0.38) IVU was categorised into quintiles: <−0.60, −0.60 to −0.37, −0.37 to −0.22, −0.22 to −0.07 and ≥−0.07 (reference) IVU. The first quintile was positively associated with ROSC (odds ratio 95% confidence interval, 9.43 1.44, 63.3).
Conclusion
Point_optimum might be located far rightwards to Point_max.RV, challenging the traditional assumption identifying Point_optimum as Point_max.LV.
We analyzed annual and seasonal frequency in aerosol type over an 8-year period (2012–2019) to identify aerosol parameter trends over four ground sites and country regions in Korea, China, and Japan ...by using the Aerosol Robotic Network (AERONET), and the satellite-based Visible Infrared Imaging Radiometer Suite (VIIRS) and Ozone Monitoring Instrument (OMI). Decreasing trends are shown for aerosol optical depth (AOD), Ångström exponent (AE), and fine mode fraction (FMF) in all countries. The decreasing trend in these data is considered to be due to a decrease in anthropogenic emissions. For the aerosol type frequency, decreases in the proportions of carbonaceous aerosols (CA) and non-absorbing aerosols (NA) were shown in the ground and satellite data, respectively. At most sites, the fractions of low AOD case (LOW) increased, whereas those of the Black and Brown Carbon (BC + BrC) category decreased. In Seoul, the fraction of LOW increased from 48.9% to 70.0%, and that of BC + BrC decreased continuously from 20.4% to 11.1% during 2012–2019. Beijing, on the other hand, showed decreasing LOW from 83.3% (2012) to 52.0% (2019), and that of BC + BrC increased significantly, from 2.4% to 26.2%. The satellite data showed that the percentage of LOW increased continuously, while that of NA aerosols decreased continuously in East Asia. A noticeable decrease in the fraction of CA was detected in China 21.5% (2013) to 11.2% (2019). In all countries, CA and NA aerosols had the greatest effect in winter and summer, respectively. We also detected significant differences between the fractions of NA and BC between the ground and satellite data. Changes in aerosol type and properties were observed concurrently in all ground and satellite data, and changes in aerosol type may explain the increasing and decreasing trends that we recorded for most parameters. Consistent results from both ground and satellite data suggest a steady decreasing in fine aerosol pollution in East Asia.
•Comparison of long-term aerosol parameter trends and type changes using both ground and satellite data•Aerosol type determination using modified criteria and weighting method for aerosol parameters•Trends of aerosol types shows decreasing effect of high-level pollution during 2012–2019.•Significant frequency changes of ‘non-absorbing’ aerosol types and low AOD cases especially in satellite data
The effect of aerosol loading on solar radiation and the subsequent effect on photosynthesis is a relevant question for estimating climate feedback mechanisms. This effect is quantified in the ...present study using ground-based measurements from five remote sites in boreal and hemiboreal (coniferous and mixed) forests of Eurasia. The diffuse fraction of global radiation associated with the direct effect of aerosols, i.e. excluding the effect of clouds, increases with an increase in the aerosol loading. The increase in the diffuse fraction of global radiation from approximately 0.11 on days characterized by low aerosol loading to 0.2–0.27 on days with relatively high aerosol loading leads to an increase in gross primary production (GPP) between 6 % and 14 % at all sites. The largest increase in GPP (relative to days with low aerosol loading) is observed for two types of ecosystems: a coniferous forest at high latitudes and a mixed forest at the middle latitudes. For the former ecosystem the change in GPP due to the relatively large increase in the diffuse radiation is compensated for by the moderate increase in the light use efficiency. For the latter ecosystem, the increase in the diffuse radiation is smaller for the same aerosol loading, but the smaller change in GPP due to this relationship between radiation and aerosol loading is compensated for by the higher increase in the light use efficiency. The dependence of GPP on the diffuse fraction of solar radiation has a weakly pronounced maximum related to clouds.
Alkaline phosphatase activity, mineralized matrix, and osteogenic-related gene expression have been shown to increase in response to bone morphogenetic protein-9 (BMP-9). In this study, spheroids ...derived from human gingival stem cells were used to determine the effects of BMP-9 on cell survival, osteogenesis, and mineralization.
: Human gingival stem cells were used to produce spheroids and then grown to concentrations of 0, 0.1, 1, 10, and 100 ng/mL with BMP-9. On days 1, 3, 5, and 7, morphological examination was carried out. A live/dead assay and Cell Counting Kit-8 was used to assess the vitality of cells. On days 7 and 14, alkaline phosphatase activity assays were carried out using a commercially available kit to examine the osteogenic differentiation of cell spheroids. Alizarin Red Staining was performed on the 7th and 14th days to evaluate mineralization, and
and
expression levels were evaluated on the 7th and 14th days using real-time polymerase chain reactions.
The BMP-9 added at the measured quantities did not appear to alter the shape of the well-formed spheroids produced by stem cells on day 1. In addition, treatment with BMP-9 at doses of 0, 0.1, 1, 10, or 100 ng/mL did not significantly alter cell diameter. Throughout the whole experimental process, viability was maintained. On day 14, the alkaline phosphatase activity in the groups dosed with 0.1, 1, 10, or 100 ng/mL was statistically higher than that in the unloaded control group (
< 0.05). According to qPCR data, the mRNA expression level of
with 1 ng/mL dosing was higher on day 7 compared to that of the unloaded control group (
< 0.05).
These findings suggest that BMP-9 can be employed to stimulate early osteogenic differentiation in stem cell spheroids.
The pellet-type catalyst demonstrates a usable region for the chemical reaction based on the reaction rate and reactant diffusivity. Therefore, achieving selective metal infiltration on the outer ...region of the support enhances the catalyst's efficiency. To address this issue, we prepared the eggshell-type Cu/ZnO/Al2O3 catalysts using the repulsion between a hydrophobic solution and a hydrophilic solution. For the methanol steam reforming reaction, the eggshell-type catalysts outperformed the homogeneously metal distributed catalysts. By analyzing the elemental distribution at both the pellet-scale and nanoscale of the catalyst, we revealed that the improved performance of the eggshell-type catalyst resulted from the selective distribution of copper particles on the outer region of the catalysts.
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•Eggshell-type Cu/ZnO/Al2O3 catalysts were prepared using hydrophobic solvent.•The eggshell-type catalyst outperformed the homogeneously distributed catalyst.•The eggshell-type catalyst resulted in the low CO concentration in the product gas.
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