Digital contact tracing and network theory to stop the spread of COVID-19 using big-data on human mobility geolocalization.

The spread of COVID-19 caused by the SARS-CoV-2 virus has become a worldwide problem with devastating consequences. Here, we implement a comprehensive contact tracing and network analysis to find an optimized quarantine protocol to dismantle the chain of transmission of coronavirus with minimal disruptions to society. We track billions of anonymized GPS human mobility datapoints to monitor the evolution of the contact network of disease transmission before and after mass quarantines. As a consequence of the lockdowns, people's mobility decreases by 53%, which results in a drastic disintegration of the transmission network by 90%. However, this disintegration did not halt the spreading of the disease. Our analysis indicates that superspreading k-core structures persist in the transmission network to prolong the pandemic. Once the k-cores are identified, an optimized strategy to break the chain of transmission is to quarantine a minimal number of 'weak links' with high betweenness centrality connecting the large k-cores.

Radiologist-Level Performance by Using Deep Learning for Segmentation of Breast Cancers on MRI Scans.

PURPOSE: To develop a deep network architecture that would achieve fully automated radiologist-level segmentation of cancers at breast MRI. MATERIALS AND METHODS: In this retrospective study, 38 229 examinations (composed of 64 063 individual breast scans from 14 475 patients) were performed in female patients (age range, 12-94 years; mean age, 52 years ± 10 [standard deviation]) who presented between 2002 and 2014 at a single clinical site. A total of 2555 breast cancers were selected that had been segmented on two-dimensional (2D) images by radiologists, as well as 60 108 benign breasts that served as examples of noncancerous tissue; all these were used for model training. For testing, an additional 250 breast cancers were segmented independently on 2D images by four radiologists. Authors selected among several three-dimensional (3D) deep convolutional neural network architectures, input modalities, and harmonization methods. The outcome measure was the Dice score for 2D segmentation, which was compared between the network and radiologists by using the Wilcoxon signed rank test and the two one-sided test procedure. RESULTS: The highest-performing network on the training set was a 3D U-Net with dynamic contrast-enhanced MRI as input and with intensity normalized for each examination. In the test set, the median Dice score of this network was 0.77 (interquartile range, 0.26). The performance of the network was equivalent to that of the radiologists (two one-sided test procedures with radiologist performance of 0.69-0.84 as equivalence bounds, P < .001 for both; n = 250). CONCLUSION: When trained on a sufficiently large dataset, the developed 3D U-Net performed as well as fellowship-trained radiologists in detailed 2D segmentation of breast cancers at routine clinical MRI.Keywords: MRI, Breast, Segmentation, Supervised Learning, Convolutional Neural Network (CNN), Deep Learning Algorithms, Machine Learning AlgorithmsPublished under a CC BY 4.0 license. Supplemental material is available for this article.

Inferring personal economic status from social network location.

It is commonly believed that patterns of social ties affect individuals' economic status. Here we translate this concept into an operational definition at the network level, which allows us to infer the economic well-being of individuals through a measure of their location and influence in the social network. We analyse two large-scale sources: telecommunications and financial data of a whole country's population. Our results show that an individual's location, measured as the optimal collective influence to the structural integrity of the social network, is highly correlated with personal economic status. The observed social network patterns of influence mimic the patterns of economic inequality. For pragmatic use and validation, we carry out a marketing campaign that shows a threefold increase in response rate by targeting individuals identified by our social network metrics as compared to random targeting. Our strategy can also be useful in maximizing the effects of large-scale economic stimulus policies.

Resveratrol-mediated reduction of collagen by inhibiting proliferation and producing apoptosis in human hypertrophic scar fibroblasts.

Hypertrophic scar (HS) is a dermal fibroproliferative disorder characterized by excessive deposition of extracellular matrix. Here, to investigate the regulative effects of resveratrol, a natural antioxidant compound, on fibroblasts from human skin HS tissue, a 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay was used to evaluate the inhibitory effect of resveratrol on cells. Cellcycle progression and apoptosis were measured by flow cytometry and Hoechst 33258 staining respectively. The hydroxyproline content and mRNA expression levels of type I and III procollagen were measured separately by ELISA and reverse transcription-polymerase chain reaction (RT-PCR). The results indicated that resveratrol significantly inhibited cell growth, arresting the cell cycle at the G1 phase and inducing apoptosis in the fibroblasts, decreasing hydroxyproline (or collagen) levels, and downregulating the expression levels of type I and III procollagen mRNA. Taken together, these data indicate that resveratrol-mediated reduction of collagen in fibroblasts is at least partially effected by causing inhibitory cell growth, cellcycle arrest, and apoptosis, and they suggest that resveratrol is a potential agent for HS treatment.

Screening of delayed-onset hearing loss in preschool children in the mid-south of China.

OBJECTIVE: Newborn hearing screening has been successfully implemented worldwide to improve the detection of hearing loss. However, delayed-onset hearing loss subsequent to newborn hearing screening remains a concern. This study aimed to investigate the prevalence of delayed-onset hearing loss in preschool children who previously passed newborn hearing screening in Hubei Province in mid-south China. DESIGN: Preschool children were screened by transient evoked otoacoustic emission (TEOAE) for delayed-onset hearing loss. Children referred after the TEOAE screening were assessed audiologically. STUDY SAMPLE: Between March 2010 and September 2011, 28 546 preschool children (4.86 ± 1.67 years old), who had passed newborn hearing screening were targeted for screening from four cities in Hubei Province, China. RESULTS: During the study period, 540 children (1.89%) were referred for audiologic assessment and 22 (0.77/1000) of them had permanent delayed-onset hearing loss, including 8 (0.28/1000) with bilateral moderate hearing loss, 10 (0.35/1000) with mild bilateral hearing loss, 2 (0.07/1000) with unilateral moderate hearing loss, and 2 (0.07/1000) with unilateral mild hearing loss. CONCLUSIONS: Despite the success of newborn hearing screening, the provision of hearing screening in preschool remains essential for identifying delayed-onset hearing loss.

[Relationship between mutation at 1 573 fragment of TNF receptor II gene and keloid].

OBJECTIVE: To study the mutations at 1 573 fragment of TNF receptor II (TNFR-II) gene in patients with keloid. METHODS: The tissue DNA was extracted from 22 samples of keloids donated by 22 patients (6 males and 16 females, aged 18-53 years), and all keloids were examined and classified by pathologist. The peripheral blood DNA was extracted from the same patients as the control. PCR was used to amplify the 1 573 fragment of TNFR-II gene from the keloid tissue DNA and peripheral blood DNA. The PCR products were sequenced directly and then compared with the GeneBank data. RESULTS: All the concentration of the extracted DNA in trial were higher than 0.50 microg/microL and the purity (A260/A280) of the extracted DNA were higher than 1.5. It closed to the magnitude of the design DNA fragment by agarose gel electrophoresis examining, and corresponded with the test requirement. Mutations at 1 573 fragment of TNFR-II gene were detected in 13 out of 22 keloids. The mutation incidence was 59.1%. Among them, 9 had point mutation at codon 1 663, accounting 40.9%. No TNFR-II gene mutation was detected in all peripheral blood samples. There were significant difference between keloids DNA and peripheral blood DNA (P < 0.01). The mutations involved point mutation, deletion and insertion as well as multisite and multitype. CONCLUSION: There is a correlation between the mutation at 1 573 fragment of TNFR-II gene and keloid.

[The relationship between RUNX3 gene mutation and keloid].

OBJECTIVE: To study the mutation in RH120480 fragment of RUNX3 gene among the Chinese patients with keloid. METHODS: 20 samples of keloids were collected with each patient's venous blood sample as normal control group. The genomic DNA was extracted from each sample. RH120480 fragment of RUNX3 gene was amplified by Polymerase Chain Reaction (PCR). The amplification products were analyzed by denaturing high-performance liquid chromatography (DHPLC). Some fragments were sequenced directly and then compared with the GenBank data. RESULTS: By DHPLC, the results of all the blood samples showed single chromatographic peak indicating homoduplexes, meanwhile the results of keloid tissue samples showed double peak indicating heteroduplexes. Through gene sequencing, 19 cases showed gene mutation among the 20 samples of keloid. The mutation incidence was 95%. Two mutation sites were detected including base A absence in 96th sites and base C insert in 279th sites. The base A absence rate was 90% (18/20) in keloid group, and 10% (2/20) in control group. The base C insert mutation rate was 95% (19/20) in keloid group, and 0% (0/20) in control group. There was significant difference in the mutation rate between two groups on the two mutation sites. CONCLUSIONS: There is a strong correlation between the RH120480 fragment of RUNX3 gene mutation and Keloid. RUNX3 gene could be possibly a scar suppressor gene (SSG).

[Comparative genomic hybridization analysis of nonsyndromic cleft lip with palate].

OBJECTIVE: To identify the genetic alterations in nonsyndromic cleft lip and palate (NSCLP). METHODS: Comparative genomic hybridization was applied to investigate the genomic imbalance (the gain or loss of genetic material) in 7 cases of NSCLP. RESULTS: It showed that the loss of chromosome DNA copies happened in chromosome 6, 7, 10, 13, 14, 16, 20, 22 and the gain of chromosome DNA copies happened in chromosome 5, 15, 18, 19. Conclusions 13q had a high frequency (71.4%) of chromosome loss. CONCLUSIONS: Abnormal chromosome DNA copies happen in all the patients with NSCLP. Most of the patients have chromosome DNA copies loss. It suggests that loss of inhibitory gene may be related to the NSCLP. The related inhibitory gene may locate in 13q.

[Effects of 5F from Pteris semipinnate L on growth of human pathological scars in nude mice].

OBJECTIVE: To investigate the effect of 5F from Pteris semipinnate L on the growth of human pathological scar in nude mice. METHODS: 5F from Pteris semipinnate L was administered at different doses in nude mouse models bearing human pathological scars. The morphology, histology, tumor growth factor-beta1 and type I collagen content of the scar tissues were examined after the administration. RESULTS: Administration of 5F significantly reduced the volume of the implanted pathological scars in the nude mouse models, and histologically, the scar tissue exhibited a transition to the normal scar architecture with decreased TGF-beta1 and type I collagen content. CONCLUSION: 5F could effectively inhibit the growth of pathological scars in nude mice.

[Mapping of the loss of heterozygosity for chromosome 1 pter-36.21 in keloid].

OBJECTIVE: The aim of this study was to investigate the loss of heterozygosity (LOH) on chromosome 1 pter-36.21 of keloid in order to locate the deletion areas probably harboring scar suppressor genes. METHODS: Using polymerase chain reaction ( PCR )-denaturing polyacrylamide gel electrophoresis, 25 samples of keloid tissues and peripheral blood were analyzed. RESULTS: 15 out of 25 samples of keloid tissues exhibited LOH in at least one microsatellite locus. There were deletions at more than one locus of one keloid tissue. No MSI was found. The frequency of LOH was remarkably higher in the keloid tissues (n = 25, 15, 60%) than in the normal control samples (n = 25, 1, 4%). The frequency of LOH in D1S243, D1S468, D1S507 and D1S199 was as following: (n= 25, 7, 28%), (n =25, 10, 40%), (n = 25, 13, 52%) and (n= 25, 3, 12%). The frequency of LOH in D1S243, D1S468, D1S507 were statistically significant. CONCLUSION: The most common LOH occurred at D1S243-D1S468-D1S507 might imply the existence of potential tumor suppressor gene of a subset of keloid , while MSI on 1 pter-36.21 may not a crucial event.

[Comparison of effects of flap delay and vascular endothelial growth factor on the viability of the rat dorsal flap].

OBJECTIVE: To compare the effects of flap delay and vascular endothelial growth factor (VEGF) on the viability of the rat dorsal flap. METHODS: Thirty rats were divided into 3 groups: saline group, flap delay group and VEGF group. The rats in flap delay group underwent flap delay by keeping bipedicle untouched, and the cranial pedicle was cut 7 days later. The rats in VEGF group were given VEGF solution locally when the flaps were elevated in the operation. The rats in saline group were given saline solution in the same way. Five days after the single pedicle flaps were performed, the flap survival rate was measured. The flap tissues were collected to measure and analyze the microvascular density, diameter and sectional area by immunochemical method. RESULTS: The flap survival rate of flap delay group was similar to that of VEGF group and there is no statistically significant difference (P>0.05). The vascular diameter of flap delay group was much larger than that of saline group and VEGF group, showing statistically significant difference (P<0.05). The vascular density of VEGF group was much higher than that of saline group and flap delay group, showing statistically significant difference (P<0.05). The vascular sectional area of flap delay group was similar to that of VEGF group (P>0.05). CONCLUSION: The change in the flap after flap delay is manifested as obvious dilatation of microvessels, while the change in the flap after the injection of VEGF is manifested as obvious vascular proliferation. Both flap delay and VEGF can increase the vascular sectional area and the viability of the flap, but the mechanism is different.

[The function of basic fibroblastic growth factor on revascularization of pearl fat graft transplantation].

OBJECTIVE: To investigate the function of basic fibroblastic growth factor on the survival of fat transplantation. METHODS: Basic fibroblastic growth factor was used in pearl fat graft transplantation on experimental animal models. Microvessels densities both on experimental sides and control sides were quantitatively researched in various periods. The growth course of vessels was observed. RESULTS: Microvessels can be observed clearly. The Microvessels densities both on experimental sides and control sides raised gradually. The density reached highest in 14 days on experimental side and in 28 days on control side, and fell down slightly later. The densities on every experimental sides were higher than that on control sides. CONCLUSIONS: Basic fibroblastic growth factor can effectually accelerate the growth of blood vessels in pearl fat graft.

[Chromosomal aberration in human keloid analyzed by comparative genomic hybridization].

OBJECTIVE: To identify the genetic alteration in human keloid. METHODS: Comparative genomic hybridization was applied in 6 cases of keloid to investigate the genomic imbalance (the gain or loss of genetic material). RESULTS: The study showed that the loss of chromosome DNA copies included chromosome, 1,7,9,13,16,17,18,19,20,22. Among them, the frequently detected chromosome loss was chromosome 1 p(66.7%), 16 (83.3%), 20 (83.3%) and 22 (83.3%). The minimum overlapping regions were 1 pter-32.2,16p13.2p11.l,20q11.1-q13.2 and 16p13.2-p11.1. Frequent gain of DNA copy numbers was not found in the special regions. CONCLUSIONS: The mapping of DNA copy variation frequency in keloid showed that there may be inhibitory genes in chromosomes 1p,16,20,22. The loss of these genes may be involved in the development and progress of keloid.

Effects of antisense oligonucleotides of PKC-alpha on proliferation and apoptosis of HepG2 in vitro.

BACKGROUND: Hepatocellular carcinoma (HCC) is one of the most common malignancies in China. The long-term survival rate of patients with HCC after prevention and management remains unsatisfactory. In order to provide a novel strategy to cure HCC, we investigated the effects of antisense oligonucleotides of PKC-alpha on proliferation and apoptosis of human hepatoma cell line HepG2 in vitro. METHODS: The human hepatocellular carcinoma cell line HepG2 was cultured and subcultured in RPMI1640 medium in vitro. PKC-alpha antisense oligonucleotides(asODN) of different concentrations with a random sequence as a control were transfected into HepG2 cells by lipofectin(LP). The cell growth index (GI) and the clone formation rate of HepG2 were detected by MTT colorimetric assay and soft agar assay, respectively. The apoptosis rate of HepG2 treated with PKC-alpha asODN was assayed by flow cytometry(FCM). The results were analyzed by SPSS 10.0 software. RESULTS: The GI of HepG2 transfected by PKC-alpha asODN with concentrations ranging from 0.10 micromol to 1.00 micromol were lower significantly than those of control groups (P<0.05). The clone formation rates of HepG2 transfected by PKC-alpha asODN from 0.05 micromol to 1.00 micromol were lower significantly than those of the control groups (P<0.01), and there was a dose-dependent relationship among them. The apoptosis rates of HepG2 treated with PKC-alpha asODN from 0.50 micromol to 1.00 micromol were significantly higher than those of the control groups. CONCLUSION: PKC-alpha asODN could inhibit the growth and proliferation of HepG2 and induce its apoptosis by blocking the cell signal transduction related to PKC-alpha in vitro, and may be potentially used in the prevention and management of recurrent and metastatic HCC.

[The TGF-alpha gene Taq I polymorphism and non-syndromic cleft lip with or without cleft palate].

OBJECTIVE: To study the association of TGF-alpha gene Taq I polymorphism and nonsyndromic cleft lip with or without cleft palate (NSCL/P) in Chinese. METHODS: 107 patients with NSCL/P and 136 healthy controls were examined for TGF-alpha/Taq I genotypes. TGF-alpha/Taq I typing was carried out by digesting the locus specific polymerase chain reaction amplified products with alleles specific Taq I restriction enzyme (PCR-RELP). RESULTS: The C2 allele frequency of TGF-alpha/Taq I in patients with NSCL/P (16%) was significantly higher than that in healthy controls (8%). The C2 genotype frequency of TGF-alpha/Taq I in NSCL/P patients with positive family history (12.5%) was significantly higher than that in healthy controls. CONCLUSION: These findings demonstrate the role of TGF-alpha as a gene of major effects in the development of nonsyndromic cleft lip with or without cleft palate clefts in human. These findings suggest that a family history of clefting may correlate with the TGF-alpha Taq I rare variation.

[The expression of EST and ER in hemangioma with its clinical value].

OBJECTIVE: To study the relationship between estrogen and the development of hemangioma. METHODS: The expression of EST and ER in samples from the thirty-eight cases of hemangioma and six cases of normal control group was examined with the immunohistochemical steptavidin peroxidase conjugated method (SP method). RESULTS: The EST in capillary hemangioma expressed significantly higher than in the cavernous hemangioma, the racemose hemangioma or the control group. Although the EST in cavernous hemangioma and racemose hemangioma also expressed higher than in the control, there are no statistical differences among them. The ER only expressed in some cases in the capillary hemangioma group. No sexual difference was shown in the expressions of the EST and the ER. CONCLUSION: This study shows that there may be a relationship existed between the estrogen and the capillary hemangioma. It may indicate that some capillary hemangioma may be possibly treated by the drugs.

[Surgical treatment of huge hemangioma in the craniofacial region].

OBJECTIVE: To summarize the therapeutic experience in removing huge craniofacial hemangioma in 135 cases and reveal the rules of repairing the damaged tissues or organs caused by the extirpation. METHODS: The procedure was to remove the focal lesion correctly, control hemorrhage, keep the stable blood volume, repair and rebuild the damaged tissues or organs reasonably. RESULTS: The focal lesion was removed rather completely without accidental injuries or deaths. The damaged tissues or organs were repaired and rebuilt quite satisfactorily. CONCLUSION: Huge craniofacial hemangioma of any type should be operated on as early as possible with sufficient preoperative preparations.