Ocular drug delivery has been a major challenge for clinical pharmacologists and biomaterial scientists due to intricate and unique anatomical and physiological barriers in the eye. The critical ...requirement varies from anterior and posterior ocular segments from a drug delivery perspective. Recently, many new drugs with special formulations have been introduced for targeted delivery with modified methods and routes of drug administration to improve drug delivery efficacy. Current developments in nanoformulations of drug carrier systems have become a promising attribute to enhance drug retention/permeation and prolong drug release in ocular tissue. Biodegradable polymers have been explored as the base polymers to prepare nanocarriers for encasing existing drugs to enhance the therapeutic effect with better tissue adherence, prolonged drug action, improved bioavailability, decreased toxicity, and targeted delivery in eye. In this review, we summarized recent studies on sustained ocular drug/gene delivery and emphasized on the nanocarriers made by biodegradable polymers such as liposome, poly lactic-co-glycolic acid (PLGA), chitosan, and gelatin. Moreover, we discussed the bio-distribution of these nanocarriers in the ocular tissue and their therapeutic applications in various ocular diseases.
A new method for accurately estimating heart rates based on a single photoplethysmography (PPG) signal and accelerations is proposed in this study, considering motion artifacts due to subjects' hand ...motions and walking. The method comprises two sub-algorithms: pre-quality checking and motion artifact removal (MAR) via Hankel decomposition. PPGs and accelerations were collected using a wearable device equipped with a PPG sensor patch and a 3-axis accelerometer. The motion artifacts caused by hand movements and walking were effectively mitigated by the two aforementioned sub-algorithms. The first sub-algorithm utilized a new quality-assessment criterion to identify highly noise-contaminated PPG signals and exclude them from subsequent processing. The second sub-algorithm employed the Hankel matrix and singular value decomposition (SVD) to effectively identify, decompose, and remove motion artifacts. Experimental data collected during hand-moving and walking were considered for evaluation. The performance of the proposed algorithms was assessed using the datasets from the IEEE Signal Processing Cup 2015. The obtained results demonstrated an average error of merely 0.7345 ± 8.1129 beats per minute (bpm) and a mean absolute error of 1.86 bpm for walking, making it the second most accurate method to date that employs a single PPG and a 3-axis accelerometer. The proposed method also achieved the best accuracy of 3.78 bpm in mean absolute errors among all previously reported studies for hand-moving scenarios.
Predator—prey mass ratio revisited Tsai, Cheng-Han; Hsieh, Chih-hao; Nakazawa, Takefumi
Functional ecology,
12/2016, Letnik:
30, Številka:
12
Journal Article
Recenzirano
Odprti dostop
Summary
Quantifying predator–prey body size relationships is key to understanding food webs. Food web models often assume that all individuals of predator species prefer the same relative body size ...of prey, using a single constant called preferred predator–prey mass ratio (preferred PPMR). In contrast, empirical studies have shown that relative prey body size in diet varies with individual predator size, challenging the food web models based on size‐invariant preferred PPMR and their predictions.
We point out that this apparent inconsistency arises because empirical PPMR in those previous studies has been measured only through dietary data (i.e. realized PPMR rather than preferred PPMR) without considering the effects of environmental prey availability, suggesting the possibility that preferred PPMR may be in fact independent of individual predator size.
Here, we present a new approach to revisit the assumption of size‐invariant preferred PPMR in food web models. The approach compares two measures of PPMR calculated from prey compositions in predator diet and environmental prey composition, respectively (i.e. realized PPMR vs. environmental PPMR). The deviations between realized and environmental PPMRs are considered as a proxy of individual variations in relative prey size preference (i.e. preferred PPMR). We apply this idea to long‐term dietary data of an omnivorous predatory fish species collected from a lake ecosystem over four decades.
Our results showed that the preferred PPMR is independent of individual predator size when the foraging mode (i.e. the major prey type) of the predator is considered while the realized PPMR is size‐dependent regardless of the foraging mode, especially when analysed analogously to previous empirical studies.
We suggest that the apparent inconsistency between theoretical assumption and empirical observation of PPMR is due to the conceptual and methodological confusion and could be resolved by distinguishing between preferred and realized PPMRs. Further, in contrast to the previous arguments based on realized PPMR, we provide the first empirical support for size‐invariant preferred PPMR. Future studies are encouraged to apply our ideas to other species/systems to test the robustness of size‐invariant preferred PPMR and to better describe food web models.
A lay summary is available for this article.
Lay Summary
Perovskite quantum dots (QDs) have efficient optical absorption and emission in the visible range, and show a strong quantum confinement effect and high external quantum efficiency. They have been at ...the forefront of next‐generation photovoltaics and optoelectronics applications. However, two major challenges associated with perovskites and their nanomaterials are poor stability (such as against moisture and polar solvents), as well as the lack of efficient nanopatterning methods. In this work, a promising approach is provided to address both of those major challenges by molecular engineering and integration of QDs with block copolymers (BCP). The BCP thermoplastic elastomers not only substantially improve the stability of perovskite QDs by encapsulating them in a highly stable and soft matrix, but also enable molecular‐level control of the alignment and assembly of perovskite QDs in the microphase‐separated BCP matrix. It is demonstrated that designing and synthesis of compatible polymer ligands for perovskite QDs is key to enabling their selective and strong interaction with the BCP matrix. The structure and molecular weight of the BCP also play an important role in the interfacial structure and optical properties of the QDs‐BCP nanocomposites. Such soft and flexible optical nanocomposites have potential applications in flexible optoelectronics, optical storage, and displays.
By designing functional polymer ligands for perovskite quantum dots and integrating them with a flexible block copolymer matrix, soft and stretchable optical materials with significantly enhanced stability and mechanical properties are achieved, which have potential applications in flexible displays, LEDs, and sensors.
Currently, Internet of Things (IoT) as an essential infrastructure proposed for industries and different applications has been popularly applied to different domains, such as healthcare and smart ...farming, for helping people to do something, aiming to improve our living environments. LoRaWAN, as a Long-Range Wide Area Network specification recommended by the LoRa Alliance, is a low power and long distance communication protocol suitable for IoT environments. This protocol adopts a widely used data encryption method, i.e., Advanced Encryption Standard (AES), developed based on powerful algebra operations and multiple encryption cycles to ensure its communication security. LoRaWAN reduces communication power by setting different transmission latencies for different end-devices; however, AES does not take into account its end device's encryption power. In this paper, a high secure but low-power consumption communication scheme for the LoRaWAN, named the Secure Low Power Communication (SeLPC) method, is proposed to further reduce end-devices' data encryption power by reducing encryption cycles of AES. In the SeLPC, encryption key and D-Box update procedure is presented to enhance security level and simplify the AES encryption process so that the power consumption can be further lowered. Comparing with the traditional AES, the analysis results show that the SeLPC can minimize the encryption power up to 26.2%. The SeLPC can also resist three attacks, including known-key, replay, and eavesdropping attacks and is practically helpful for use in LoRaWAN IoT environments.
Predicting the dynamics of harvested species is essential for assessing stock status and establishing index-based management strategies. However, conventional approaches for short-lived species ...predict dynamics poorly, possibly because unobserved interactions with other species and abiotic factors are often treated as noise. Alternatively, the empirical dynamic modeling (EDM) approach, which uses the time delays of the observed states to compensate for unobserved interactions, may improve the predictions for short-lived species. We test this idea using time series data of two federally managed, short-lived penaeid shrimp species, whose abundances were surveyed over 30 years (1987-2018) across the US Gulf of Mexico. We show that (i) abundance dynamics of these annual shrimp stocks are well-predicted by EDM, (ii) the dynamics are spatially similar across most of the gulf, and (iii) the stock dynamics are characterized by nonlinear density-dependent interaction and vary with temperature. Our findings suggest that EDM may be more responsive than single-species, catch-at-age models in assessing the stock dynamics for short-lived penaeid shrimp species.
Acinetobacter baumannii is a prevalent pathogen that can rapidly acquire resistance to antibiotics. Indeed, multidrug-resistant A. baumannii is a major cause of hospital-acquired infections and has ...been recognised by the World Health Organization as one of the most threatening bacteria to our society. Resistance-nodulation-division (RND) type multidrug efflux pumps have been demonstrated to convey antibiotic resistance to a wide range of pathogens and are the primary resistance mechanism employed by A. baumannii. A component of an RND pump in A. baumannii, AdeT1, was previously demonstrated to enhance the antimicrobial resistance of Escherichia coli. Here, we report the results of experiments which demonstrate that wild-type AdeT1 does not confer antimicrobial resistance in E. coli, highlighting the importance of verifying protein production when determining minimum inhibitory concentrations (MICs) especially by broth dilution. Nevertheless, using an agar-based MIC assay, we found that propionylation of Lys280 on AdeT1 renders E. coli cells more resistant to erythromycin.
There is increasing global incidence of highly metastatic melanoma and therapeutic strategies like those focusing on the downstream beta-catenin/MITF axis of invading melanoma cells are urgently ...needed. Targeting endoplasmic reticulum (ER) stress can promote cancer cell death and inhibit epithelial mesenchymal transition (EMT) in metastatic tumors. This study aimed to determine if Honokiol could promote ER stress-dependent apoptosis and regulate metastatic melanoma. The therapeutic efficacy of Honokiol was assessed using the highly metastatic melanoma xenograft mouse model for peritoneal metastasis and evaluated by computed tomography imaging. The ER stress marker, Calpain-10, delineated a novel proteolytic cleavage enzyme, while CHOP/GADD153-regulated apoptosis was used for gene silencing to determine the role of the β-catenin/MITF axis in melanoma cells. The results showed that Honokiol effectively decreased peritoneal dissemination and organ metastasis via ER stress activation and EMT marker inhibition. Knockdown Calpain-10 or CHOP/GADD153 blocked all of the biological effects in Honokiol-induced β-catenin/MITF cleavage, ERSE or TCF/LEF luciferase activity, and β-catenin kinase activity. These findings suggest that Honokiol can significantly thwart the progression of highly metastatic melanoma using the β-catenin/MITF axis via prompt Calpain-10 and CHOP/GADD153 regulated cascades.
•Honokiol inhibits the growth and metastasis of melanoma both in vitro and in vivo.•Honokiol induced ER stress CHOP activation and reduced MITF, β-catenin, and CDK2 expressions in animal melanoma tissues.•Honokiol-induced CHOP/GADD153 regulated β-catenin activation.•Honokiol enhanced Calpain10 and MITF-m interaction and caused MITF-m cleavage.•High expressions of MITF, β-catenin, and CDK2 decreased the overall survival probability of melanoma.
: The increase in the global population of hemodialysis patients is linked to aging demographics and the prevalence of conditions such as arterial hypertension and diabetes mellitus. While previous ...research in hemodialysis has mainly focused on mortality predictions, there is a gap in studies targeting short-term hospitalization predictions using detailed, monthly blood test data.
This study employs advanced data preprocessing and machine learning techniques to predict hospitalizations within a 30-day period among hemodialysis patients. Initial steps include employing K-Nearest Neighbor (KNN) imputation to address missing data and using the Synthesized Minority Oversampling Technique (SMOTE) to ensure data balance. The study then applies a Support Vector Machine (SVM) algorithm for the predictive analysis, with an additional enhancement through ensemble learning techniques, in order to improve prediction accuracy.
The application of SVM in predicting hospitalizations within a 30-day period among hemodialysis patients resulted in an impressive accuracy rate of 93%. This accuracy rate further improved to 96% upon incorporating ensemble learning methods, demonstrating the efficacy of the chosen machine learning approach in this context.
This study highlights the potential of utilizing machine learning to predict hospital readmissions within a 30-day period among hemodialysis patients based on monthly blood test data. It represents a significant leap towards precision medicine and personalized healthcare for this patient group, suggesting a paradigm shift in patient care through the proactive identification of hospitalization risks.
Rationale
Accumulating evidence has linked prolonged exposure to heavy metals to cancer occurrence in the urinary system. However, the specific biological mechanisms responsible for the association ...of heavy metals with the unusually high incidence of upper tract urothelial carcinoma in Taiwan are complex and incompletely understood.
Methods
To elucidate the specific biological mechanism and identify molecular indicators of the unusually high association of upper tract urothelial carcinoma with heavy metal exposure, protein expression following the treatment of T24 human bladder carcinoma and RT4 human bladder papilloma cell line models with arsenic (As) and cadmium (Cd) was studied. Proteomic changes in these cell models were integrated with data from a human bladder cancer (BLCA) tissue proteome to identify possible protein indicators of heavy metal exposure.
Results
After mass spectrometry based proteomic analysis and verification by Western blotting procedures, we identified 66 proteins that were up‐regulated and 92 proteins that were down‐regulated in RT4 cell extracts after treatment with As or Cd. Some 52 proteins were up‐regulated and 136 proteins were down‐regulated in T24 cell extracts after treatment with Cd. We further confirmed that down‐expression of the PML (promyelocytic leukemia) protein was sustained for at least 75 days after exposure of bladder cells to As. Dysregulation of these cellular proteins by As was associated with three biological pathways. Immunohistochemical analyses of paraffin‐embedded BLCA tissue slides confirmed that PML protein expression was decreased in BLCA tumor cells compared with adjacent noncancerous epithelial cells.
Conclusions
These data suggest that PML may play an important role in the pathogenesis of BLCA and may be an indicator of heavy metal exposure in bladder cells.
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