Nonrepresentativeness of Human Mobility Data and its Impact on Modeling Dynamics of the COVID-19 Pandemic: Systematic Evaluation.

BACKGROUND: In recent years, a range of novel smartphone-derived data streams about human mobility have become available on a near-real-time basis. These data have been used, for example, to perform traffic forecasting and epidemic modeling. During the COVID-19 pandemic in particular, human travel behavior has been considered a key component of epidemiological modeling to provide more reliable estimates about the volumes of the pandemic's importation and transmission routes, or to identify hot spots. However, nearly universally in the literature, the representativeness of these data, how they relate to the underlying real-world human mobility, has been overlooked. This disconnect between data and reality is especially relevant in the case of socially disadvantaged minorities. OBJECTIVE: The objective of this study is to illustrate the nonrepresentativeness of data on human mobility and the impact of this nonrepresentativeness on modeling dynamics of the epidemic. This study systematically evaluates how real-world travel flows differ from census-based estimations, especially in the case of socially disadvantaged minorities, such as older adults and women, and further measures biases introduced by this difference in epidemiological studies. METHODS: To understand the demographic composition of population movements, a nationwide mobility data set from 318 million mobile phone users in China from January 1 to February 29, 2020, was curated. Specifically, we quantified the disparity in the population composition between actual migrations and resident composition according to census data, and shows how this nonrepresentativeness impacts epidemiological modeling by constructing an age-structured SEIR (Susceptible-Exposed-Infected- Recovered) model of COVID-19 transmission. RESULTS: We found a significant difference in the demographic composition between those who travel and the overall population. In the population flows, 59% (n=20,067,526) of travelers are young and 36% (n=12,210,565) of them are middle-aged (P<.001), which is completely different from the overall adult population composition of China (where 36% of individuals are young and 40% of them are middle-aged). This difference would introduce a striking bias in epidemiological studies: the estimation of maximum daily infections differs nearly 3 times, and the peak time has a large gap of 46 days. CONCLUSIONS: The difference between actual migrations and resident composition strongly impacts outcomes of epidemiological forecasts, which typically assume that flows represent underlying demographics. Our findings imply that it is necessary to measure and quantify the inherent biases related to nonrepresentativeness for accurate epidemiological surveillance and forecasting.

CD47 Promotes Human Glioblastoma Invasion Through Activation of the PI3K/Akt Pathway.

Cluster of differentiation 47 (CD47) overexpression is common in various malignancies. This study investigated whether CD47 promotes human glioblastoma invasion and, if so, the underlying mechanisms involved. CD47 expression was found to be stronger in tissues of patients with glioblastoma and in various cancer cell lines than in normal controls. CD47 downregulation via siRNA suppressed invasion in vitro, whereas CD47 overexpression through plasmid transfection exerted the opposite effect. However, overexpression or knocking down of CD47 had no effect on cell proliferation. Moreover, CD47 expression was related to Akt phosphorylation at the cellular molecular level. Suppression of Akt with a specific inhibitor impaired the invasion ability of CD47-overexpressing cells, indicating that stimulation of the PI3K/Akt pathway served as the downstream regulator of CD47-triggered invasion. These results suggest that CD47 might be a useful predictor of poor prognosis and metastasis and a potential target for treating glioblastomas.

MicroRNA-623 Targets Cyclin D1 to Inhibit Cell Proliferation and Enhance the Chemosensitivity of Cells to 5-Fluorouracil in Gastric Cancer.

The dysregulation of microRNAs (miRNAs) plays an important function in the onset and progression of gastric cancer (GC). In addition, aberrantly expressed miRNAs affect the chemosensitivity of GC cells to chemotherapeutic drugs. Hence, miRNA-based targeted therapy might be applied to treat patients with GC exhibiting chemotherapeutic resistance. In this study, miRNA-623 (miR-623) expression was downregulated in GC tissues and cell lines. Functional analysis showed that the restored miR-623 expression could inhibit the proliferation of GC cells and enhance their chemosensitivity to 5-FU via the cell apoptosis pathway. Cyclin D1 (CCND1) was identified as a direct target gene of miR-623 in GC. The overexpressed CCND1 in GC tissues was negatively correlated with miR-623 level. The recovered CCND1 expression counteracted the effects of miR-623 on GC cell proliferation, chemosensitivity, and 5-FU-induced apoptosis. Thus, our results suggest that miR-623 might function as a tumor suppressor in GC and could be a promising therapeutic target for patients with GC, especially those with chemotherapeutic resistance.

Identification of therapeutic targets for breast cancer using biological informatics methods.

The present study aimed to investigate the modular mechanisms underlying breast cancer and identify potential targets for breast cancer treatment. The differentially expressed genes (DEGs) between breast cancer and normal cells were assessed using microarray data obtained from the Gene Expression Omnibus database. Gene ontology (GO) and pathway enrichment analyses were performed in order to investigate the functions of these DEGs. Subsequently, the protein-protein interaction (PPI) network was constructed using the Cytoscape software. The identified subnetworks were further analyzed using the Molecular Complex Detection plugin. In total, 571 genes (241 upregulated and 330 downregulated genes) were found to be differentially expressed between breast cancer and normal cells. The GO terms significantly enriched by DEGs included cell adhesion, immune response and extracellular region, while the most significant pathways included focal adhesion and complement and coagulation cascade pathways. The PPI network was established with 273 nodes and 718 edges, while fibronectin 1 (FN1, degrees score, 39), interleukin 6 (IL6; degree score, 96) and c-Fos protein (degree score, 32) were identified as the hub proteins in subnetwork 2. These dysregulated genes were found to be involved in the development of breast cancer. The FN1, IL6 and FOS genes may therefore be potential targets in the treatment of breast cancer.

IL-33/ST2 pathway contributes to metastasis of human colorectal cancer.

Interleukin-33 (IL-33) was recently implicated in cancer pathogenesis. However, the possible effect of IL-33 on tumor progression of colorectal cancer (CRC), which is one of the most commonly diagnosed and lethal cancers worldwide, was still unclear. Here we evaluated the potential role of IL-33/ST2 pathway in metastasis of human CRC. We found an elevated expression of IL-33 and ST2 in tumor tissues of CRC patients. Higher expressions of IL-33 and ST2 were observed in poor-differentiated human CRC cells. Of note, IL-33 stimulation promoted the invasion of human CRC cells in a dose dependent manner. Enhanced IL-33/ST2 signaling promoted CRC metastasis, while attenuated IL-33/ST2 signaling decreased CRC metastasis. In consistent, enforced IL-33 expression in human CRC cells enhanced their growth, metastasis and reduced the survival time in nude mice, while decreased IL-33 expression in human CRC cells inhibited their growth, metastasis and prolonged the survival time in nude mice. Finally, we observed an increased expression of IL-6, CXCR4, MMP2 and MMP9 in response to IL-33/ST2 signaling in human CRC cells, which were crucial for the enhanced metastasis by IL-33 stimulation. Collectively, our findings demonstrated that IL-33/ST2 pathway could contribute to the metastasis of human CRC, which could enlarge the understanding of CRC pathogenesis and provide clues for developing new CRC therapeutics.

Purification and characterization of a novel antifungal protein secreted by Penicillium chrysogenum from an Arctic sediment.

A fungal strain, Penicillium chrysogenum A096, was isolated from an Arctic sediment sample. Its culture supernatant inhibited mycelial growth of some plant pathogenic fungi. After saturation of P. chrysogenum A096 culture supernatant with ammonium sulfate and ion exchange chromatography, a novel antifungal protein (Pc-Arctin) was purified and identified by matrix assisted laser desorption ionization-time of flight-time of flight-mass spectrometry (MALDI-TOF-TOF-MS). The gene encoding for Pc-Arctin consisting of 195 nucleotides was cloned from P. chrysogenum A096 to confirm the mass spectrometry result. Pc-Arctin displays antifungal activity against Paecilomyces variotii, Alternaria longipes, and Trichoderma viride at minimum inhibitory concentrations (MIC) of 24, 48, and 192 ng/disc, respectively. Pc-Arctin was most sensitive to proteinase K and then to trypsin but insensitive to papain. Pc-Arctin possesses high thermostability and cannot be antagonized by common surfactants, except for sodium dodecyl sulfate (SDS). Divalent ions, such as Mn(2+), Mg(2+), and Zn(2+), inhibited the antifungal activity of Pc-Arctin. Hemagglutination assays showed that Pc-Arctin had no hemagglutinating or hemolytic activity against red blood cells (RBC) from rabbits, rats, and guinea pigs. Therefore, Pc-Arctin from Arctic P. chrysogenum may represent a novel antifungal protein with potential for application in controlling plant pathogenic fungal infection.

A new cestode (Tetraphyllidea: Phyllobothriidae) in elasmobranchs from the Taiwan Strait.

In total, 20 fanrays, Platyrhina sinensis (Rajiformes: Rhinobatidae), collected from the Taiwan Strait, were examined. A new phyllobothriid genus and species (Tetraphyllidea: Phyllobothriidae) was found and described. Biotobothrium platyrhina n. gen., n. sp. is assigned to the Rhinebothriinae Euzet, 1953, because it possesses 4 stalked bothridia that are each divided by septa into numerous small facial loculi but that lack apical suckers. The new genus and species is clearly different from any other in Rhinebothriinae in that each bothridium bears 2 sets of 5 small facial loculi, with 1 set located at each of the distal ends of the bothridium, rather than facial loculi throughout the entire distal surface of the bothridium, as is seen in all other genera in the subfamily. This character has not been previously reported for members of Rhinebothriinae. In addition, the testicular arrangement in the anterior quarter of the proglottid is unique. The posterior range of the vas deferens almost reaches the ovarian bridge, and the morphology of the cirrus sac and several other morphological characters are at variance with presently described species in the subfamily.

[Research progress in magnetic thermosensitive polymeric microspheres].

As a new type of functional material, magnetic thermosensitive polymeric microspheres offer high potential application in various fields, particularly in bioengineering and biomedical fields. In this review, the development of synthesis and application of magnetic thermosensitive polymeric microspheres was summarized, and the research trends were also discussed.

A new pseudophyllidean from a freshwater fish, Gambusia affinis, in China.

Coelobothrium gambusiense n. sp. (Bothriocephalidae) was collected and described from the intestine of the freshwater fish Gambusia affinis (Baird and Girard) (Poeciliidae) in Fujian Province, Peoples' Republic of China. It is the first record of Coelobothrium in China. The parasite closely resembles Coelobothrium monodi Dollfus, 1970, from Capoeta damascina (Valenciennes, Cyprinidae) in Iran and Coelobothrium oitense Kugi and Matsuo, 1990, from Tribolodon hakonensis (GUnther, Cyprinidae) in Japan in general morphological characters, the scolex, and the incomplete proglottids. The third species of Coelobothrium is distinguished from its congeners by its much shorter strobila, presence of a neck, a bilobed ovary instead of a transversely elongated ovary, larger eggs, different final host and locality, and other morphological characters.

Saccocoelium megasacculum n. sp., a new haploporid trematode from Liza carinatus in the Taiwan strait.

Saccocoelium megasacculum n. sp. (Digenea: Haploporidae) was collected from the intestine of the mugilid fish. Liza carinatus (Cuvier and Valenciennes), in the Taiwan Strait. It is the first record of Saccocoelium in China. The parasite most closely resembles Saccocoelium obesum Looss, 1902 and Saccocoelium tensum Looss, 1902 in general morphology and body size, but it is easily distinguished from them in having a larger hermaphroditic sac in relation to body size; larger eggs; smaller pharynx, testis, ovary, and vitellaria; and a uterine seminal receptacle instead of a true seminal receptacle.