Microfluidic Chip-Assisted Upconversion Luminescence Biosensing Platform for Point-of-Care Virus Diagnostics.

Epidemics caused by multiple viruses continue to emerge, which have brought a terrible impact on human society. Identification of viral infections with high sensitivity and portability is of significant importance for the screening and management of diseases caused by viruses. Herein, a microfluidic chip (MFC)-assisted upconversion luminescence biosensing platform is designed and fabricated for point-of-care virus detection. Upconversion nanoparticles with excellent stability are successfully synthesized as luminescent agents for optical signal generation in the portable virus diagnostic platform. The relevant investigation results illustrate that the MFC-assisted virus diagnostic platform possesses outstanding performance such as good integration, high sensitivity (1.12 pg mL-1), ease of use, and portability. In addition, clinical sample test result verifies its more prominent virus diagnostic properties than commercially available rapid test strips. All of these thrilling capabilities imply that the designed portable virus diagnostic platform has great potential for future virus detection applications.

Design and Scalable Fabrication of Liquid Metal and Nano-Sheet Graphene Hybrid Phase Change Materials for Thermal Management.

Here, a paraffin/liquid metal (LM)/graphene hybrid thermal composite material with a high thermal-conductivity as well as  high latent heat is developed. The paraffin is encapsulated in calcium alginate, which produces leakage-free phase change material (PCM) capsules. LM is filled among the gaps of PCM capsules to enhance overall heat conduction. Graphene nano-sheets coating attains efficient heat dissipation because of its high spectral emissivity (>91%) in the spectrum of the mid-infrared region. The developed material is verified to have strong compatibility and durable stability. The composite is utilized as a thermal buffer (TB) for central processing unit thermal management to demonstrate the synergy of these superior thermal properties. In certain cases, active cooling normally used could be replaced by the developed TB without any energy consumption for thermal management, demonstrating a completely passive cooling strategy. Compared to traditional heat sink active cooling, general energy savings of 10.4-26.3% could thus be achieved by the developed composite in wider operating conditions, proving its potential for more efficient and sustainable data center cooling alongside thermal management of other ground-based electrical/electronic equipment.

Real time observation of the formation of hollow nanostructures through solid state reactions.

We demonstrate the formation of hollow nickel germanide nanostructures of Ni-Ge core-shell nanoparticles by solid state reactions. The structural evolutions of nickel germanide hollow nanostructures have been investigated in real-time ultrahigh vacuum transmission electron microscopy (UHV-TEM). Annealed above 450 °C, the nonequilibrium interdiffusion of core and shell species occurred at the interface; thus, Ni germanide hollow nanostructures were formed by solid state reactions involving the Kirkendall effect. In addition, the different hollow nanostructures formed from different core diameters of Ni-Ge core-shell nanoparticles have been studied. Also, we propose the mechanism with effects of the size and annealing duration on the solid state reactions based on the Kirkendall effect.

[Effect of alexandrite laser treatment for hair removal in Tibet mini-pigs].

OBJECTIVE: To observe the histological and ultrastructural changes of the skin and hair follicles following hair removal by alexandrite laser in Tibet mini-pigs. METHODS: Twelve healthy Tibet mini-pigs with dark hair were treated with alexandrite laser for hair removal. The skin specimens were taken immediately and at 1 h and 1, 3, 5, 10, 15, 30, 60 days after the laser treatment for observation under optical and transmission electron microscope. RESULTS: Laser hair removal resulted in extensive coagulation necrosis, carbonization and falling of the subcutaneous hair shafts, and some of the cells in the outer root sheath and hair bulb underwent degenerative and necrotic changes. One hour after laser treatment, the cells in the outer root sheath and bulb exhibited nuclear condensation, fragmentation and or karyolysis characteristic of cell apoptosis. The cell apoptosis reached the peak level on day 3 after the laser exposure, accompanied by endothelial degeneration in the hair papilla vessels, edema and lymphocyte infiltration in the dermal tissues. Tissue reaction and inflammation were relieved on day 5, and the dermal tissue and follicles recovered their normal structures on day 10. At 60 days after the treatment, the hair follicles decreased markedly but the structure of the residue follicles remained normal. CONCLUSION: Alexandrite laser exposure results in selective destruction of the follicles by inducing direct coagulation and cell apoptosis to achieve permanent hair removal. Tibet mini-pigs with black hair can be used as the animal model of clinical laser hair removal.

Morphological observation of nuclear sub-localization of human angiogenin in HUVECs.

Angiogenin, a potent angiogenic factor, was cloned and expressed by Escherichia coli and then purified with gel filtration chromatography. Approximately 90% pure angiogenin was obtained to generate a monoclonal antibody. Using western immunoblotting and ELISA, we confirmed that monoclonal antibody C46 secreted from hybridoma cells stably and specifically binds to angiogenin. The fused protein angiogenin-EGF was then expressed in HUVECs, and the subcellular localization of the recombinant protein was determined by confocal microscopy and TEM assay. Recombinant angiogenin was found to mainly concentrate in the pars granulosa of the nucleus, where the protein accumulates to form ribonucleoprotein particles.

Hand-assisted laparoscopic total colectomy for slow transit constipation.

PURPOSE: Current medical treatments for slow transit constipation (STC) are often ineffective, and total colectomy with ileorectal anastomosis has been the procedure of choice for selected patients with refractory STC. Today, minimally invasive approaches are being utilized in a greater number of procedures as surgeons become more familiar with the techniques involved. The aim of this study was to assess the safety and utility of hand-assisted laparoscopic total colectomy for STC. METHOD: From January 2002 to December 2005, 44 women presented with complaints of intractable constipation and failed to respond to medical treatment. Slow transit constipation was diagnosed after a series of examinations, including a colonic transit test, anal manometry, balloon expulsion test, and barium enema. All eligible patients underwent a hand-assisted laparoscopic total colectomy with ileorectal anastomosis. Main outcome measures included the operative time, conversion to open procedure, blood loss, time to return of flatus, length of postoperative hospital stay, and complications. RESULT: The mean operative time was 197 min (range, 125-295 min). The mean estimated blood loss was 113 ml (range, 100-300 ml). The mean day of first time to flatus was 2 days, and the mean hospital stay was 7.6 days. There was no conversion to an open procedure and no surgical mortality. In the following period, two patients developed intestinal obstruction, which underwent exploratory laparotomy. However, some 39 patients (88.6%) expressed excellent or good in satisfaction. CONCLUSION: Hand-assisted laparoscopic total colectomy could be a safe and efficient technique in the treatment of STC.

Stapled hemorrhoidectomy versus conventional excision hemorrhoidectomy for acute hemorrhoidal crisis.

We compared the safety and clinical outcomes of stapled hemorrhoidectomy and conventional excision hemorrhoidectomy in the treatment of acute hemorrhoidal crisis, and analyzed various factors associated with complications in stapled hemorrhoidectomy. Forty patients underwent stapled hemorrhoidectomy and forty underwent conventional excision hemorrhoidectomy. All had the operation under local anesthesia with conscious sedation within 24 h of admission. The length of surgery, hospital stay, disability, postoperative pain, and the use of analgesics were significantly less for patients in the stapled hemorrhoidectomy group. Stapled hemorrhoidectomy did not significantly increase the rate of complications. Five patients in the stapled group (12.5%) required further surgical intervention: three with thrombosed hemorrhoids and two with recurrent prolapse. No serious complications were reported in either group. Patient satisfaction was similar in the two groups. Increased age was identified as a factor that significantly elevated the risk of complications in the stapled group (OR, 1.06; 95% CI, 1.01-1.13). Anemia and time between the onset of prolapsed hemorrhoids and hospital admission were also risk factors for complications, although they were not significant. Stapled hemorrhoidectomy is a feasible treatment for selected patients with an acute hemorrhoidal crisis and has a similar complication rate to that of conventional excision hemorrhoidectomy. Stapled hemorrhoidectomy is superior in less-postoperative pain, shorter operation time, shorter hospital stay, and earlier return to normal activity. However, we suggest that older patients with anemia or a prolonged hemorrhoidal crisis are unsuitable for stapled hemorrhoidectomy.

Heterotopic mesenteric ossification after total colectomy for bleeding diverticulosis of the colon--a rare case report.

Heterotopic bone formation within an abdominal incision is a rare sequela of abdominal surgery. Only a few previous reports have noted heterotopic ossification in the mesentery of the small intestine and peri-ileostomy. Here, we report the case of a 60-year-old man who underwent emergent laparotomy and total colectomy with end ileostomy and developed this condition 1 month postoperatively. Heterotopic ossification in the peri-ileostomy tissue caused stenosis of the ileostoma. Laparotomy for re-anastomosis due to a large bone formation at an abdominal midline scar is very difficult and results in a massive abdominal wall defect. Therefore, we used a lower transverse incision to avoid the site of bone formation and resected the terminal ileum with its ossified mesentery. Then, we successfully carried out an anastomosis between the ileum and the rectum. The possible pathogenesis is a metaplastic mechanism of differentiation of immature multipotent mesenchymal cells. Our case provides the experience of treatment and new perspective on currently held hypotheses of heterotopic bone formation.

[Role of ciliary neurotrophic factor in regeneration of severed facial nerve of cats].

OBJECTIVE: To study the role of extrinsic (CNTF) in the regeneration of severed facial nerve in cats. METHOD: The facial nerve in temporal bone of adult cats were severed and the severed ends were connected with CNTF or saline applied at the connection. Electrophysiological examination and immunocytochemistry were performed with immunoelectron microscope for morphological analysis at 2, 4 and 8 weeks after the operation. RESULTS: Two weeks after operation, both CNTF and saline groups failed to exhibit muscular excitement by facial nerve stimulation, but the amount of myelinated nerve fibers had statistical difference between the two groups (P<0.05). At 4 weeks, the latency of the facial muscle excitement was 7.832+/-2.695 ms in CNTF group and 16.120+/-3.516 ms in saline group, and the average number of myelinated axons was significantly different between the two groups (1,435+/-318 vs 957+/-269, P<0.05). At the 8th weeks, the latency of facial muscle excitement was reduced to 3.125+/-0.165 ms in CNTF group and to a comparable level of 3.095+/-0.178 ms in saline group (P>0.05), and the average number of myelinated axons increased to 1,695+/-283 and 1,543+/-320 respectively in the two groups (P>0.05). Significant increase of Schwann cells was noted in both groups at this stage. CONCLUSION: Local application of CNTF may enhance facial early-stage nerve regeneration in adult cats, but its long-term effects remain unclear.

Isolated rectal diverticulum complicating with rectal prolapse and outlet obstruction: case report.

The occurrence of rectal diverticula is very rare, with only sporadic reports in the literature since 1911. Symptomatic rectal diverticula are encountered even less frequently. Treatments of these complicated events range from conservative treatments to major surgical interventions. We present a hitherto unreported occurrence of isolated rectal diverticulum complicated with rectal prolapse and outlet obstruction. Delorme's procedure resulted in subsidence of symptoms and resolution of the diverticulum. It provides a minimal invasive surgical technique to successfully address the reported malady.

Changes in the expression of angiotensin II type 1 receptor in the development of liver fibrosis.

OBJECTIVE: To detect the expression of angiotensin II type 1 receptor (AT1R) in the different stages of human liver fibrosis. METHODS: The morphology and ultrastructure of hepatic stellate cells (HSC) in hepatic sinusoids were studied by transmission electron microscopy, collagen I (col I) was tested by immunohistochemical method, an indirect immunofluorescence labeling method was used to detect AT1R, and semiquantitative RT-PCR was used to detect AT1R mRNA. RESULTS: Positive expression of AT1R was mainly distributed in the periphery of hepatic lobules and in the cytoplasm of HSC in the sinusoids. In normal liver tissue from 12 cases, positive expression of AT1R was seen in 8, whereas in 18 fibrotic livers, all showed positive expression. Cells that positively expressed AT1R were significantly more abundant in the fibrotic liver group than in the normal liver group (P < 0.001), and were significantly increased with an increase in the collagenous surface area. The relative expression level of AT1R mRNA in the fibrotic liver group was also higher than in the normal liver group (P < 0.01). CONCLUSIONS: The expressions of both AT1R and AT1R mRNA increased significantly with the degree of liver fibrosis, so angiotensin II and its receptor are probably important in the development of liver fibrosis.

[Pathological changes of lungs in patients with severity acute respiratory syndrome].

OBJECTIVE: To evaluate the progression in morphologic changes of lungs in SARS patients. METHODS: Four cases of SARS with lung tissue samples available (including one for ultrastructural examination) were enrolled into the study. Histochemical study for VG, Masson, reticulin, orcein, PAS, sirius red stains and immunohistochemical study for vimentin, desmin, smooth muscle actin, HHF-35, CD34, F8, collagen types I and III were also performed. RESULTS: According to the morphologic changes, lung lesions in SARS were subcategorized into 3 phases: acute exudative inflammation, fibrous proliferation and the final fibrotic stage. Two cases belonged to the acute exudative phase, in which the course was less than 20 days. The principal lesions consisted of acute alveolar exudative inflammation, hyperplasia of alveolar epithelium, necrosis, alveolar hyaline membrane formation, alveolar desquamation and focal fibroplasia. The acute exudative protein was PAS-positive. There was an increase in reticulin fiber formation. The reactive fibroblasts were highlighted by desmin and vimentin. One case belonged to the fibroproliferative stage, in which the course was around 25 days. Major lesions included proliferative interstitial pneumonia with early pulmonary fibrosis. There was also evidence of organizing pneumonia, with an increase in reticulin fiber formation, which had a glomeruloid appearance on special stain. The mesenchymal cells showed either myofibroblastic (which expressed desmin, HHF-35, smooth muscle actin and vimentin) or fibroblastic (which expressed vimentin only) differentiation. Fibroelastosis and fibroplasia was also noted. The remaining case belonged to the fibrotic stage, in which the course was around 75 days. The main features included diffuse fibrosis and honeycomb change, which were highlighted by sirius red stain. Immunohistochemistry showed mainly types I and IV collagen fibers. In all lesions, there was also an increase of number of CD68-positive macrophages. CONCLUSIONS: The morphologic progression in lungs of SARS patients is characterized by the development of increased fibrosis. The primitive mesenchymal cells, hyperplastic alveolar epithelial cells and macrophages play an important role in the pathogenesis.

[Development of toxin targeting to VEGF-KDR].

OBJECTIVE: To develop toxin targeting vascular endothelial growth factor receptor II (VEGF-II/KDR) fused with a KDR-binling peptide screened from peptide library. METHODS: By affinity to KDR molecular which expressed specifically by new born vascular endothelial cell, peptides to KDR were screened from C7 peptide library by phage display. Among them, a peptide binding to KDR with high affinity termed as P5 was selected and fused to the N-terminal of Shiga toxin subunit A (StxA). The protein (P5-StxA) was expressed in E. coli. RESULTS: ELISA and Western blot were applied to characterize the binding interaction between the fusion protein, P5-StxA and KDR. Cytotoxicity assay showed that P5-StxA maintained similar toxicity to cell as StxA. In the model of angiogenesis, P5-StxA inhibited selectively VEGF-induced growth of preexisting vessels of the chick chorioallantoic membrane. CONCLUSION: These studies demonstrate the small peptide, P5, maybe be used as carrier of toxin targeting to KDR.

[Pathological and ultramicrostructural changes of tissues in a patient with severe acute respiratory syndrome].

OBJECTIVE: To study the morphological, ultramicrostructural and pathological changes of tissues from a patient with severe acute respiratory syndrome (SARS). METHODS: One autopsy case of diagnosed SARS was investigated. Lung puncture was performed immediately after the patient died, and the autopsy was done after 12 h. The specimens from lymph nodes, spleen, small intestine, colon and bone marrow were studied by immunohistochemical technique. The antibodies used included CD20, CD45RO (UCHL-1), CD4, CD8, CD68 and CD34. RESULTS: The principal lesions of the SARS case consisted of acute lobular intrastitial pneumonia, hyaloid membranes of pulmonic alveoli and hyperplasia and shedding of alveolar epithelium of. Virus-like inclusions occasionally contained cytoplasm of the alveolar epithelium, which were positive by histochemical staining. The adjacent blood-vessels were changed by hyperplasia and enlargement. The structures of lymph nodes and spleen were damaged with lymph follicles depletion and splenic nodules atrophy. The specific changes included reduction of lymphocytes and hyperplasia of histiocytes, depletion of the follicles of small intestine and colon wall, decreased hyperplasia of the bone marrow and increased number of the megakaryocyte. Meanwhile, in the immunohistochemical study, CD(20)(+) B cells were fully expressed in lymph nodes and spleen, and the CD45RO (UCHL-1)(+) T cells were scatteredly expressed. The number of CD4(+) help T cell was markedly decreased, while the number of CD8+ poisonal T cells increased, and the ratio of the former and latter was no more than 0.5. Under the electronic microscopy observation, virus-like particles with 80 - 160 nm diameter and halo or garland envelope were found in mononuclear macrophage and cytoplasm of alveolar epithelium. CONCLUSION: The specific lesions of SARS consist of lobular intrastitial pneumonia with the formation of hyaline membranes of lung, haemorrhage, necrosis, inflammation of blood vessels and the damages of extralung lymphohemopioetic system. The damages were very similar to the pathological features of tissues infected by human immunodeficiency virus, in which numbers of T cells decreased and CD(4)(+) T cell/CD(8)(+) T cell ratio was no more than 0.5. According to the virus-like particles found in lung of the SARS case, it is considered that these virus-like particles may be a new kind of coronavirus which caused the "atypical pneumonia".

[The effect of calcium ionophore on dendritic cells derived from peripheral blood mononuclear cells].

AIM: To explore the effect of calcium ionophore (CI) on dendritic cells (DC) derived from peripheral blood monocytes. METHODS: Peripheral blood monocytes from healthy donors were treated with 100 microg/L rhGM-CSF, 100 microg/L rhGM-CSF plus (10 microg/L) CI, and 100 microg/L rhGM-CSF plus (100 microg/L) respectively. After cultivation of 40 hours, cellular morphology was observed under light microscope and electron microscope. Surface markers on treated PBMCs were analyzed by flow cytometry. MTT colorimetry was used to detect proliferation of autologous T cells. RESULTS: Peripheral blood monocytes treated with 100 microg/L rhGM-CSF plus 100 microg/L CI for 40 hours showed typical morphology of DCs. Simultaneously there was a decrease in CD14 expression and increase in HLA-DR, CD40, CD83 and CD86 expressions on these cells. In addition, PBMCs treated with 100 microg/L rhGM-CSF pass 100 microg/L CI for 40 hrs. Could evidently stimulate proliferation of autologous T cells. CONCLUSION: CI can markedly enhance transformation of peripheral blood monocytes induced by GM-CSF into DCs.