Superspreading k-cores at the center of COVID-19 pandemic persistence

The spread of COVID-19 caused by the recently discovered SARS-CoV-2 virus has become a worldwide problem with devastating consequences. To slow down the spread of the pandemic, mass quarantines have been implemented globally, provoking further social and economic disruptions. Here, we address this problem by implementing a large-scale contact tracing network analysis to find the optimal quarantine protocol to dismantle the chain of transmission of coronavirus with minimal disruptions to society. We track billions of anonymized GPS human mobility datapoints from a compilation of hundreds of mobile apps deployed in Latin America to monitor the evolution of the contact network of disease transmission before and after the confinements. As a consequence of the lockdowns, peoples mobility across the region 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, the optimal 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. Our results demonstrate the effectiveness of an optimal tracing strategy to halt the pandemic. As countries race to build and deploy contact tracing apps, our results could turn into a valuable resource to help deploy protocols with minimized disruptions.

Differences of DNA copy number changes between hyperplastic scar and keloid / 中国组织工程研究

BACKGROUND: Clinical genetics and molecular biology studies have shown that the occurrence and development of the keloid is closely related to the inheritance. However, it remians unclear if the same is ture to the hypertrophic scar. OBJECTIVE: To investigate similadties and differences of genetic alteration between the hyperplastic scar and the keloid, DESIGN, TIME AND SETTING: A contrast observational experiment was performed in Guangdong Medical College between March 2007 and December 2008.MATERIALS: Scar samples were taken from 16 patients (in-patient and out-patient) in the Department of Plastic Surgery, the Affiliated Hospital of Guangdong Medical College, with10 patients with hypertrophic scars (3 males and 7 females, 20-50 years old) and 6 patients with keloids (1 males and 5 females, 19-46 years old). METHODS: The DNA of both hyperplastic scar and keloid tissues was extracted to investigate, using comparative genomic hybridization technique, the genomic imbalance (the lose or amplification of genetic material), so as to make a comparative study on differences of the DNA copy number changes between the two. RESULTS: Neither altofrequent loss nor amplification of DNA copy number was found in any specific DNA region of hyperplastic scar tissues; as for the keloid, special DNA altofrequent loss regions were also not found, but altofrequent DNA copy number loss regions presented in 1, 16, 20 and 22 chromosomes. Comparatively, the keloid presented much higher loss rate of the DNA copy number in 1,16,20 and 22 chromosomes than the hyperplastic scar (P < 0.05).CONCLUSION: The hyperplastic scar has no conspicuous DNA copy number lose or amplification compared with the keloid, which indicates that the occurrence and development of the hyperplastic scar may not have any direct relation with the inheritance.

Relationship between MTHFR gene mutation and keloid / 中华医学美学美容杂志

Objective To study the MTHFR gene (677 gene loci and 1298 gene loci) mutations in Chinese patients with keloid. Methods The tissue DNA was extracted from 20 samples of keloids. and peripheral blood samples from the same patients were employed as the control. Polymerase chain reaction(PCR) was used to amplify the Mthfr 677 gene loci and Mthfr 1298 gene loci from the keloid tissue DNA and peripheral blood DNA. and the PCR products were sequenced directly and then compared with the GenBank data. Results Mutations were detected in 17 out of 20 keloids on Mthfr 677 gene loci, the mutation incidence was 85.0 %. Mutations were detected in 13 out of 20 keloids on Mthfr 1298 gene loci, and the mutation incidence was 65.0 %. The mutation involved point mutation, deletion and insetion as well as multisite and multitype. No MTHFR gene mutation was detected in all peripheral blood samples . Conclusion There is a strong correlation between the MTHFR gene (677 gene loci and 1298 gene loci) mutation and keloid.

Association between TGF-α gene BaraH Ⅰ polymorphism and nonsyndromic cleft lip with or without cleft palate / 中华医学美学美容杂志

Objective Nonsyndromic cleft lip with or without cleft palate(NSCL/P)is a common craniofacial birth defect which results in lifelong medical and social consequences.Although Asians have the highest birth prevalence of oral-facial clefts,the majority of gene mapping studies of cleft lip with or without cleft palate(CL/P)have been in European or Ameriean Caucasians.Therefore,the obiective of this study was to evaluate association between transforming growth factor alpha(TGF-α)gene BamH Ⅰ polymorphism and NSCL/P in Chinese.Methods 107 patients with NSCL/P and 136 healthy controls were examined for TGF-α/BamH Ⅰ genotypes.TGF-α/BamH Ⅰ typing was carried out by digesting the locus specific polymerase chain reaction amplified products with alleles specific BamH Ⅰ restriction enzyme(PCR-RELP).Resuits A1 allele frequency was 0.06 and A2 allele frequency was 0.94 in the controls.A1 allele frequency was 0.14 and A2 allele frequency was 0.86 in patients with NSCL/P(x2=8.27,df=1,P＜0.05).A1 allele frequency was 0.17 and A2 allele frequency was 0.83 in the bilateral cleft lip with or without cleft palate.A1 allele frequency was 0.13 and A2 allele frequency was 0.87 in the unilateral cleft lip with or without cleft palate(x2=0.36,df=1,P＞0.05).There was no statistically significant between the case with family history and the case without family history(x2=0.34,df=1,P＞0.05).Conclusions The above data demonstrate that there is evidence for the association of TGF-α polymorphism with development of NSCL/P in Chinese.

Research development of heterogeneous extracellular matrix / 国际生物医学工程杂志

Extracellular matrix(ECM) is the research focus in organize engineering, The configuration?component and mechanics enviroment of ECM is fit for the growth and metastasis of the cell. Heterogeneous ECM is not widely used in clinical treatment for immunocompetence and ethics. This paper introduces the production?organize configuration? immunocompetence and the clinical application of heterogeneous ECM.

Surgical treatment of huge hemangioma in the craniofacial region / 中华整形外科杂志

<p><b>OBJECTIVE</b>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.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>The focal lesion was removed rather completely without accidental injuries or deaths. The damaged tissues or organs were repaired and rebuilt quite satisfactorily.</p><p><b>CONCLUSION</b>Huge craniofacial hemangioma of any type should be operated on as early as possible with sufficient preoperative preparations.</p>

Expression and Significance of PCNA in Different Parts of Keloid / 中国医师杂志

Objective To analyze proliferating cell nuclear antigen(PCNA) index in invasive, proliferative,aged parts of keloid to explore the mechanism of keloid invasive growth characteristics. Methods PCNA in 10 cases of keloid and 10 cases of normal skin was detected by immunohistochemical staining, and the PCNA index of different parts in keloid and normal skin was compared. Results The PCNA index of invasive part in keloid was obviously higher than that of proliferative,aged parts of keloid and normal skin (P

Surgical Treatment of Skin Cancer in Facies in the Elderly / 中国医师杂志

Objective To study the surgical repair mode of skin cancer in facies in aged patients. Methods The modes of surgical repair in 216 cases of aged patients with skin cancer in facies were analyzed. Results The special characteristics of physiology and pathology and the facies anatomy in the elderly determined the complexity of surgical repair. The surgical mode of excision and suture was the safest and the most efficacious. Skin flap transfer could mostly satisfy the function requirements of facies for the wound that was not able to be sutured after excision. Free skingrafting was applicable to the case that the deep tissue was not invaded by the tumor and the general condition of the patients was not much good. Conclusion The order of surgical repair modes for skin cancer in the facies in the elderly is excision and suture, skin flap transfer, and free skingrafting. Local skin flap must be the primary source as the selection of the skin flap is concerned. The suitable axial pattern skin flap or musculo-cutaneous flap can be selected according to the different section of the facies while there is no suitable local tissue.

Effects of pentifylline on hypertrophic scars in rabbit ears / 中华医学美学美容杂志

Objective To observe the effects of pentifylline on hypertrophic scars in the rabbit ears. Methods An animal model for hypertrophic scars was established and treated with pentifylline in different concentrations or saline on day 49. Hypertrophic index, growth of fibroblasts and production of collagen in the section were quantitatively determined with an image analysis system. Results Hypertrophic index was found to be decreased in the pentifylline-treated group (P

Repairing of defect in forehead with frontalis musculocutaneous island flap / 中华医学美学美容杂志

Objective To introduce a better operation method to repair the skin and soft tissue defects in the forehead.Methods This kind of frontalis musculocutaneous flap was applied to repair the skin and soft tissue defects in the forehead in 8 cases.The flap was designed carefully according to the shape and the size of the focal lesion before the operation. The maximum area of the flap was 2.9cm?1.6cm, and the minimum area was 1.2cm?1cm. The full flap contained muscle in its proximal area and skin, muscle, and fascia in its distal one. A muscular pedicle with appropriate length was outlined on the paramedian and lateral forehead. The pedicle was composed of frontalis muscle fibers, the terminal part of the frontal branches of the superficial temporal artery, and some small branches from the supraorbital and the supratrocheal arteries. The body of the flap was designed into triangle shape. Full thickness skin was incised around the inverted pattern of the defect. The skin of the paramedian and lateral aspect was then undermined laterally. Superficial dissection was carried out in a subcutaneous layer. The flap was undermined beneath the galea and frontalis muscle just external to the skull. The muscle pedicle was prepared by incising a parallel horizontal incision. Careful attention should be taken so as not to injure the vascular pedicle. At that time, the supraorbital and supratrocheal arteries were carefully ligated to obtain complete hemostasis. Then the flap was advanced and transferred down to cover the wound in the forehead. The donor site could be sutured directedly by undermining the margins of the defect without much difficuties. Results All flaps in 8 cases survived. Venous congestion was observed in early postoperative period in only one case. But the flap survived completely after proper management in final healing. Follow-ups were made from 6 months and 12 months after operations. The color and texture of the flaps were similar to the adjacent skin in the forehead. The shapes were satisfying. Conclusions This kind of flap is a much better method for the repairing of some small or moderate defects in the forehead. It can be easily operated and allow a rapid aesthetic restoration.

The characteristics of blood supply of the medial antebrachial neurocutaneous nerve and it' s significance in designing flap / 中华显微外科杂志

Objective To supply morphologic basis for designing the medial antebrachial neurocutaneou vascular flap. Methods Microanatomy and transparent specimens made by colored latex injection were applied to study the surgical anatomy of the medial antebrachial neurocutaneous nerve (MAN) and it's relationship to basilic vein, the origin, orientation,caliber of neurovascular cutaneous perforators and it's nutrient pattern to the MAN. Results The MAN got its blood supply by paraneural vessels which constituted of 4 cutaneous perforators' The paraneural vessels supply not only the MAN,but also it's adjacent flap. The MAN was accompanied by basilic vein about 1 cm away from it. Conclusion Along basilic vein,medial antebrachial neurocutaneous vascular flap could be designed and used to repair soft tissue defects around the elbow and wrist