Efficient spiking neural network design via neural architecture search.

Spiking neural networks (SNNs) are brain-inspired models that utilize discrete and sparse spikes to transmit information, thus having the property of energy efficiency. Recent advances in learning algorithms have greatly improved SNN performance due to the automation of feature engineering. While the choice of neural architecture plays a significant role in deep learning, the current SNN architectures are mainly designed manually, which is a time-consuming and error-prone process. In this paper, we propose a spiking neural architecture search (NAS) method that can automatically find efficient SNNs. To tackle the challenge of long search time faced by SNNs when utilizing NAS, the proposed NAS encodes candidate architectures in a branchless spiking supernet which significantly reduces the computation requirements in the search process. Considering that real-world tasks prefer efficient networks with optimal accuracy under a limited computational budget, we propose a Synaptic Operation (SynOps)-aware optimization to automatically find the computationally efficient subspace of the supernet. Experimental results show that, in less search time, our proposed NAS can find SNNs with higher accuracy and lower computational cost than state-of-the-art SNNs. We also conduct experiments to validate the search process and the trade-off between accuracy and computational cost.

A New Practical Method Based on MRI to Individually Localize the Transverse-Sigmoid Sinus Junction in Retrosigmoid Craniotomy: A Retrospective Before-After Study.

Background: Although the asterion has long been used as a skeletal surface marker of the transverse-sigmoid sinuses junction (TSSJ) point in the retrosigmoid approach, abundant evidence shows that the relationship between asterion and TSSJ point varies greatly. In recent years, new technologies have been developed, such as neuronavigation and three-dimensional volume rendering imaging, that can guide in exposing the TSSJ point individually. However, they are not only expensive but also difficult to apply in emergency surgery. Objective: To introduce a quick, practical, and low-cost new method for locating the TSSJ point precisely. Methods: In this retrospective before-after study, the test group located the TSSJ point with our new method during a 6-month period, while the control group used asterion as a surface landmark to estimate the TSSJ during the preceding 6 months. The primary outcome is the immediate exposure rate of the TSSJ point by the initial burr hole. Results: There were 60 patients in both control and test groups as no significant difference in the general clinical characteristics of both groups were observed. The new three-step method significantly increased the TSSJ exposure rate by initial burr hole compared with the control group (96.67% vs. 53.33%, P = 0.0002). Moreover, the total bone loss and craniotomy duration were significantly reduced by the new method. Incidence of sinus injury (10% vs. 6.6%), post-operation infection (3.33% vs. 3.33%), and CSF leakage (3.33% vs. 0%) were similar. Conclusions: The novel three-step approach accurately locates TSSJ points in retrosigmoid craniotomy, reduces bone defects, saves time, and does not increase the risk of sinus injury, infection, and CSF leakage.

Multiphase flow detection with photonic crystals and deep learning.

Multiphase flows are ubiquitous in industrial settings. It is often necessary to characterize these fluid mixtures in support of process optimization. Unfortunately, existing commercial technologies often fail to provide frequent, accurate, and cost-efficient data necessary to enable process optimization. Here we show a new physics-based concept and testing with lab and field prototypes leveraging photonic crystals for real-time characterization of multiphase flows. In particular, low power (~1 mW) microwave transmission through photonic crystals filled with fluid mixtures may be interrogated by deep learning analysis techniques to provide a fast and accurate characterization of phase fraction and flow morphology. Moreover when these flow characteristics are known, the flow rate is accurately inferred from the differential pressure necessary for the flow to pass through the photonic crystal. This insight provides a basis to develop a unique class of inexpensive, accurate, and convenient techniques to characterize multiphase flows.

Ultrathin h-BN/Bi2MoO6 heterojunction with synergetic effect for visible-light photocatalytic tetracycline degradation.

Herein, a series of ultrathin h-BN/Bi2MoO6 heterojunction with excellent photocatalytic activity has been firstly prepared via a feasible solvothermal method. Our results suggest that the optimized photocatalyst possesses a high degradation ratio of tetracycline (TC), oxytetracycline (OTC) and doxycycline (DC) up to 99.19%, 95.28% and 91.04% under visible-light irradiation, respectively. We highlight that the outstanding photocatalytic activity is mainly attributed to the prominent performance of tetracycline adsorption on h-BN and the dominant visible-light absorption by Bi2MoO6 as well as the effective photogenerated carrier separation induced by the synergetic effect between h-BN and Bi2MoO6. Moreover, DFT calculations reveal that the built-in electric field formed between h-BN and Bi2MoO6 gives rise to the separation of carriers and the polarization of tetracycline molecules. Last but not the least, the specific process and micro-mechanism of the photocatalytic tetracycline degradation under visible-light driven have also been illuminated. The present work pioneers the application of ultrathin h-BN/Bi2MoO6 heterojunction as a novel tetracycline degradation photocatalyst and further guides the design of more visible-light photocatalysts.

Distribution of Diego blood group alleles and genotypes in the Chinese Korean population and sequence-based identification.

OBJECTIVE: To investigate Diego blood group alleles in the Chinese Korean population. The Diego blood group system plays an important role in transfusion medicine, but the distribution of the blood group in many Chinese ethnic populations remains unclear. METHODS: Sequence Specific Primer Polymerase Chain Reaction (SSP-PCR) was used for Diego genotyping and sequence-based typing PCR (PCR-SBT) was used to verify single nucleotide polymorphisms in the coding region of SLC4A1 starting from exon 19. Nine hundred and ten samples from the Chinese Korean population were investigated. RESULTS: The frequency of the DI*01 and DI*02 alleles in the Chinese Korean population was 0.0516 and 0.9484, respectively. The most predominant genotype was DI*02/DI*02, with a frequency of 90.22 % (821/910). The frequency of DI*01/DI*02 was 9.23 % (84/910) and that of DI*01 /DI*01 was 0.55 % (5/910). The genotype distributions of the Diego blood group conformed to the Hardy-Weinberg equilibrium (P > 0.05). CONCLUSION: The data obtained from this study will be helpful for the creation of a donor database to provide antigen-negative blood to patients with allo-antibodies. Genotyping can be used as a substitute for the serological technique when antisera are unavailable and is suitable for screening a large number of donors for rare-blood-group databases.

Quantifying Induced Polarization of Conductive Inclusions in Porous Media and Implications for Geophysical Measurements.

Induced polarization (IP) mapping has gained increasing attention in the past decades, as electrical induced polarization has been shown to provide interesting signatures for detecting the presence of geological materials such as clay, ore, pyrite, and potentially, hydrocarbons. However, efforts to relate complex conductivities associated with IP to intrinsic physical properties of the corresponding materials have been largely empirical. Here we present a quantitative interpretation of induced polarization signatures from brine-filled rock formations with conductive inclusions and show that new opportunities in geophysical exploration and characterization could arise. Initially tested with model systems with solid conductive inclusions, this theory is then extended and experimentally tested with nanoporous conductors that are shown to have a distinctive spectral IP response. Several of the tests were conducted with nano-porous sulfides (pyrite) produced by sulfate-reducing bacteria grown in the lab in the presence of a hydrocarbon source, as well as with field samples from sapropel formations. Our discoveries and fundamental understanding of the electrode polarization mechanism with solid and porous conductive inclusions suggest a rigorous new approach in geophysical exploration for mineral deposits. Moreover, we show how induced polarization of biologically generated mineral deposits can yield a new paradigm for basin scale hydrocarbon exploration.

Enhancement in Power Conversion Efficiency of GaAs Solar Cells by Utilizing Gold Nanostar Film for Light-Trapping.

Light trapping, caused by the introduction of metallic nanoparticles, has been demonstrated to enhance photo-absorption in GaAs solar cells. In this study, we successfully synthesized gold nanostar thin film with hot spots and obtained a notable improvement of power conversion efficiency (PCE) in single-junction and three-junction high-performance GaAs solar cells by incorporating the poly (3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) layer, which enables a much stronger light trapping capability and scattering enhancement than conventional metal nanostructures. Increases of 5.2% and 3.94% in short circuit current density (Isc) were achieved for single-junction cells and three-junction cells while the enhancement in cell PCE was 3.85 and 2.50%, respectively. The relationship between the optical characteristics, the distribution density of the gold NSs and the performance of GaAs solar cells was systemically investigated.

Evaluation of the learning curve for transurethral plasmakinetic enucleation and resection of prostate using a mentor-based approach

ABSTRACT Objective To analyze the mentor-based learning curve of one single surgeon with transurethral plasmakinetic enucleation and resection of prostate (PKERP) prospectively. Materials and Methods Ninety consecutive PKERP operations performed by one resident under the supervision of an experienced endourologist were studied. Operations were analyzed in cohorts of 10 cases to determine when a plateau was reached for the variables such as operation efficiency, enucleation efficiency and frequency of mentor advice (FMA). Patient demographic variables, perioperative data, complications and 12-month follow-up data were analyzed and compared with the results of a senior urologist. Results The mean operative efficiency and enucleation efficiency increased from a mean of 0.49±0.09g/min and 1.11±0.28g/min for the first 10 procedures to a mean of 0.63±0.08g/min and 1.62±0.36g/min for case numbers 31-40 (p=0.003 and p=0.002). The mean value of FMA decreased from a mean of 6.7±1.5 for the first 10 procedures to a mean of 2.8±1.2 for case numbers 31-40 (p<0.01). The senior urologist had a mean operative efficiency and enucleation efficiency equivalent to those of the senior resident after 40 cases. There was significant improvement in 3, 6 and 12 month’s parameter compared with preoperative values (p<0.001). Conclusions PKERP can be performed safely and efficiently even during the initial learning curve of the surgeon when closely mentored. Further well-designed trials with several surgeons are needed to confirm the results.

Evaluation of the Learning Curve for Transurethral Plasmakinetic Enucleation and Resection of Prostate Using a Mentor-based Approach.

OBJECTIVE: To analyze the mentor-based learning curve of one single surgeon with transurethral plasmakinetic enucleation and resection of prostate (PKERP) prospectively. MATERIALS AND METHODS: Ninety consecutive PKERP operations performed by one resident under the supervision of an experienced endourologist were studied. Operations were analyzed in cohorts of 10 cases to determine when a plateau was reached for the variables such as operation efficiency, enucleation efficiency and frequency of mentor advice (FMA). Patient demographic variables, perioperative data, complications and 12-month follow-up data were analyzed and compared with the results of a senior urologist. RESULTS: The mean operative efficiency and enucleation efficiency increased from a mean of 0.49±0.09g/min and 1.11±0.28g/min for the first 10 procedures to a mean of 0.63±0.08g/min and 1.62±0.36g/min for case numbers 31-40 (p=0.003 and p=0.002). The mean value of FMA decreased from a mean of 6.7±1.5 for the first 10 procedures to a mean of 2.8±1.2 for case numbers 31-40 (p<0.01). The senior urologist had a mean operative efficiency and enucleation efficiency equivalent to those of the senior resident after 40 cases. There was significant improvement in 3, 6 and 12 month's parameter compared with preoperative values (p<0.001). CONCLUSIONS: PKERP can be performed safely and efficiently even during the initial learning curve of the surgeon when closely mentored. Further well-designed trials with several surgeons are needed to confirm the results.

Extraperitoneal versus transperitoneal laparoscopic radical cystectomy for selected elderly bladder cancer patients: a single center experience.

OBJECTIVE: This study reports the initial experience of extraperitoneal laparoscopic radical cystectomy (ELRC) and compared with transperitoneal laparoscopic radical cystectomy (TLRC) in the treatment of selected elderly bladder cancer patients. PATIENTS AND METHODS: A total of forty male bladder cancer patients who underwent ELRC (n=19) or TLRC (n=21) with ureterocutaneostomy were investigated. Demographic parameters, perioperative variables, oncological outcomes and follow-up data were retrospectively analyzed. RESULTS: A significantly shorter time to exsufflation (1.5±0.7 vs 2.1±1.1 d; p=0.026) and liquid intake (1.8±0.9 vs 2.8±1.9 d; p=0.035) were observed in the ELRC group compared with the TLRC group. The incidence of postoperative ileus in the ELRC group was lower than the TLRC group (0 vs 9.5%). However, the difference had no statistical significance (p>0.05). The removed lymph node number in the ELRC group was significantly lower than the TLRC group (p<0.001). No significant differences were observed between the two groups in the overall and cancer-free survival rates (p>0.05). CONCLUSIONS: ELRC seems to be a safe and feasible surgical strategy for the selected elderly bladder cancer patients with ≤T2 disease. The surgical and oncological efficacy of the ELRC is similar to that of the TLRC, but with faster intestinal function recovery. Further studies with a large series including different urinary diversions are needed to confirm our results and to better evaluate the benefit of ELRC in bladder cancer patients.

Extraperitoneal versus transperitoneal laparoscopic radical cystectomy for selected elderly bladder cancer patients: a single center experience

ABSTRACT Objective: This study reports the initial experience of extraperitoneal laparoscopic radical cystectomy (ELRC) and compared with transperitoneal laparoscopic radical cystectomy (TLRC) in the treatment of selected elderly bladder cancer patients. Patients and Methods: A total of forty male bladder cancer patients who underwent ELRC (n=19) or TLRC (n=21) with ureterocutaneostomy were investigated. Demographic parameters, perioperative variables, oncological outcomes and follow-up data were retrospectively analyzed. Results: A significantly shorter time to exsufflation (1.5±0.7 vs 2.1±1.1 d; p=0.026) and liquid intake (1.8±0.9 vs 2.8±1.9 d; p=0.035) were observed in the ELRC group compared with the TLRC group. The incidence of postoperative ileus in the ELRC group was lower than the TLRC group (0 vs 9.5%). However, the difference had no statistical significance (p>0.05). The removed lymph node number in the ELRC group was significantly lower than the TLRC group (p<0.001). No significant differences were observed between the two groups in the overall and cancer-free survival rates (p>0.05). Conclusions: ELRC seems to be a safe and feasible surgical strategy for the selected elderly bladder cancer patients with ≤ T2 disease. The surgical and oncological efficacy of the ELRC is similar to that of the TLRC, but with faster intestinal function recovery. Further studies with a large series including different urinary diversions are needed to confirm our results and to better evaluate the benefit of ELRC in bladder cancer patients.

Retroperitoneal Laparoendoscopic Single-Incision Radical Nephrectomy Without Special Platforms: A Single-Center Initial Experience.

OBJECTIVES: To describe the initial experience of retroperitoneal laparoendoscopic single-incision radical nephrectomy (LESI-RN) without special platforms and use of conventional laparoscopic instruments and assess the safety and feasibility of LESI-RN. SUBJECTS AND METHODS: Twenty patients who underwent LESI-RN were enrolled in this study. A 5-cm arc skin incision was performed at the midpoint between the costal arch and iliac crest on the midaxillary line. Trocars of 10, 5, and 11 mm were placed at the middle, left end, and right end of the arc incision, respectively. Demographic parameters and perioperative data were retrospectively analyzed and compared with the patients who underwent conventional retroperitoneal laparoscopic radical nephrectomy (LRN). RESULTS: The LESI-RN patients had a significantly lower visual analogue scale (4.4 ± 1.9 versus 5.6 ± 1.4; P = .031) and analgesic requirement (18.5 ± 11.2 versus 28.6 ± 16.1; P = .026) compared with the conventional LRN group. The operation time in the LESI-RN group was longer than that in the conventional LRN group (P = .001). The two procedures were essentially similar in terms of the time to liquid intake and hospital stay after operation (P > .05). CONCLUSIONS: LESI-RN is a safe and feasible surgical strategy, which combines the common principles of using straight instruments and working triangulation in conventional LRN with advantages of cosmesis and minimal invasiveness in laparoendoscopic single-site surgery. The surgical and oncological efficacy of LESI-RN is similar to that of conventional LRN but with significantly improved control of postoperative pain and cosmetic results.

Thulium Laser Enucleation Versus Plasmakinetic Enucleation of the Prostate: A Randomized Trial of a Single Center.

PURPOSE: To compare the safety and efficacy of thulium laser enucleation of the prostate (ThuLEP) with plasmakinetic enucleation of the prostate (PKEP). METHODS: A total of 127 patients with benign prostatic hyperplasia (BPH) were randomized to either ThuLEP (n = 61) or PKEP (n = 66). All patients were assessed preoperatively and followed up at 3, 6, and 12 months postoperatively. Baseline characteristics of the patients, perioperative data, postoperative outcomes, and complications were recorded. RESULTS: The decrease in hemoglobin level and the catheter time were statistically significantly lower in the ThuLEP group compared with the PKEP group (0.80 ± 0.49 vs 0.99 ± 0.52, p = 0.037, and 1.85 ± 0.94 vs 2.28 ± 1.34, p = 0.042). There were no statistical differences in complications between the two groups (p > 0.05). There was a significant improvement in 3, 6, and 12 months' parameters compared with preoperative values (p < 0.001). Assessment at the 12-month follow-up showed no difference in urinary parameters between the two groups. CONCLUSIONS: ThuLEP and PKEP are both safe and efficient procedures for the treatment of patients with BPH. Compared with PKEP, ThuLEP provided less risk of hemorrhage and shorter catheter time, although the differences may be of little clinical relevance. Further well-designed trials with extended follow-up and larger sample size are needed to draw final conclusions about the efficacy of the two procedures.

MTDH is an oncogene in multiple myeloma, which is suppressed by Bortezomib treatment.

Metadherin (MTDH) is identified as an oncogene in multiple cancers including breast cancer, bladder cancer and endometrial cancer. However, the function of MTDH in multiple myeloma (MM) is still unexplored. In this study, we disclose that MTDH is an oncogene in MM. This is characterized by an elevation mRNA level of MTDH and chromosomal gain of MTDH locus in MM cells compared to normal samples. Moreover, MTDH expression significantly increased in MMSET translocation (MS) subgroup, one of the high-risk subgroups in MM, and was significantly correlated with MM patients' poor outcomes in Total Therapy 2 (TT2) cohort. Further knockdown of MTDH expression by shRNA in MM cells induced cell apoptosis, inhibited MM cells growth in vitro and decreased xenograft tumor formation in vivo. Interestingly, opposite to TT2, MM patients with high-MTDH expression showed favorable survival outcomes in the TT3 cohort, while Bortezomib treatment was the major difference between TT2 and TT3 cohort. Furthermore we proved that Bortezomib suppressed pre- and post-transcription levels of MTDH expression of MM cells in vitro and in vivo. Finally, our studies demonstrated that MTDH is a transcriptional gene of MMSET/NFκB /MYC signaling in MM cells, which is inhibited by Bortezomib treatment.

[Structural components of Chinese medicine and pharmacology network: systematical overall regulation on pathological network].

Development of the disease is the result of several factors involved in biological network changes. The nature of drug intervention is to regulate these pathological changes to the normal range. Advantages of traditional Chinese medicine (TCM) are to integrally and systematically regulate this biological networks and systematic pathology through multi-targets, multi-levels, multi-channels. Structural components TCM provides the controlled and precise basis "substance" for this regulation and also to clarify the "truth" of the nature of the regulation by the network pharmacology. Network pharmacology provides new strategy for the research on mechanism of structural components TCM. This study not only reflects the overall characteristics of the development of the disease, but also fully embodies the essence of TCM for preventing and treating diseases through changing traditional model on "one drug, one gene, one disease". This paper explores systematically the integration essence, features and research strategies of structural components TCM and the network pharmacology, understand the interaction of structural components TCM and body from the perspective of the overall concept of improving or restoring the balance of.biological networks. It is effective measure to reveal the structure of a multi-component for regulating biological networks mechanisms, and also provide new ideas and methods for further scientific research and innovation of structural component TCM.

[Effect of different composition structures of total paeony glycoside component and total phenolic acid component of Chuanxiong Rhizome on human umbilical vein endothelial cells with hypoxic injury].

OBJECTIVE: To study the effect of different composition structures of total paeony glycoside (TPG) component and total phenolic acid of Ligusticum chuanxiong ( TLPA) on sodium dithionite (Na2S2O4) -induced human umbilical vein endothelial cells (HUVEC) hypoxic injury. The baseline geometric proportion was used to design different components structure. And then the best structure of components by cell injury model were optimized. METHOD: A HUVEC hypoxic injury model was established by being induced of Na2S2O4. Cell viability was measured by MTI colorimetric method, intracellular superoxide dismutase (SOD) activity, malondialdehyde (MDA), lactate dehydrogenase( LDH) levels, nitric oxide (NO) contents were measured by kits. At last, Western blot analysis was used to detect the expression of two proteins, Bcl-2 and Bax. RESULT: Compared with the model group, TPG component, TLPA component at different composition structures can significantly increase SOD activity and decrease MDA, LDH, NO levels (P < 0.01, P < 0.05). Paeoniae Radix Rubra and Chuanxiong Rhizoma components can downregulate the expression of Bax protein and upregulate the expression of Bcl-2 protein. The ratio of Bcl-2 and Bax was significantly increased (P < 0 01, P < 0 05), it means that cell apoptosis was inhibited. The results indicate that among all the component composition structures, TPG and TLPA component at the proportion of 8: 2 had the best protection on hypoxic injury of endothelial cells. CONCLUSION: TPG component and TLPA component can resist HUVEC hypoxia injury, the protective effect was the most evident under the structure of 8: 2, which may be due to the inhibition of intracellular lipid peroxidation and cell apoptosis.

Current status of diagnosis and treatment of bladder cancer in China - Analyses of Chinese Bladder Cancer Consortium database.

OBJECTIVE: To investigate current status of diagnosis and treatment of bladder cancer in China. METHODS: A database was generated by Chinese Bladder Cancer Consortium (CBCC). From January 2007 to December 2012, 14,260 cases from 44 CBCC centers were included. Data of diagnosis, treatment and pathology were collected. RESULTS: The average age was 63.5 year-old and most patients were male (84.3%). The most common histologic types were urothelial carcinoma (91.4%), adenocarcinoma (1.8%), and squamous carcinoma (1.9%). According to 1973 and 2004 WHO grading system, 42.0%, 41.0%, and 17.0% of patients were grade 1, 2, and 3, and 16.0%, 48.7%, and 35.3% of patients were papillary urothelial neoplasms of low malignant potential, low, and high grade, respectively. Non-muscle invasive bladder cancer (NMIBC) and muscle invasive bladder cancer (MIBC) were 25.2% and 74.1%, respectively (0.8% not clear). Carcinoma in situ was only 2.4%. Most patients were diagnosed by white-light cystoscopy with biopsy (74.3%). Fluorescence and narrow band imaging cystoscopy had additional detection rate of 1.0% and 4.0%, respectively. Diagnostic transurethral resection (TUR) provided detection rate of 16.9%. Most NMIBCs were treated with TUR (89.2%). After initial TUR, 2.6% accepted second TUR, and 45.7%, 69.9%, and 58.7% accepted immediate, induced, and maintenance chemotherapy instillation, respectively. Most MIBCs were treated with radical cystectomy (RC, 59.7%). Laparoscopic RCs were 35.1%, while open RC 63.4%. Extended and standard pelvic lymph node dissection were 7% and 66%, respectively. Three most common urinary diversions were orthotopic neobladder (44%), ileal conduit (31%), and ureterocutaneostomy (23%). Only 2.3% of patients accepted neo-adjuvant chemotherapy and only 18% of T3 and T4 patients accepted adjuvant chemotherapy. CONCLUSION: Disease characteristics are similar to international reports, while differences of diagnosis and treatment exist. This study can provide evidences for revisions of the guideline on bladder cancer in China.

Re-entrant solidification in polymer-colloid mixtures as a consequence of competing entropic and enthalpic attractions.

In polymer-colloid mixtures, non-adsorbing polymers dispersed with much larger colloids provide a universal yet specific entropic attraction between the colloids. Such so-called depletion interaction arises from an osmotic-pressure imbalance caused by the polymers and is considered to be independent of temperature. Here we show that, for the most commonly used polymer-colloid depletion systems, the polymer undergoes a crossover from non-adsorbing to adsorbing and that, consequently, the effective colloidal interactions depend on temperature. We also find that a combination of the enthalpic (polymer bridging) and entropic (polymer exclusion) interactions, both attractive, leads to a re-entrant regime where the colloids are dispersed and form solids both on heating and on cooling. We provide a simple model to explain the observed transitions and to fill the theoretical gap at the polymer-adsorption crossover. Our findings open possibilities for colloidal self-assembly, the formation of colloidal crystals and glasses, and the behaviour of temperature-controlled viscoelastic materials.

Changes in dendritic cells and dendritic cell subpopulations in peripheral blood of recipients during acute rejection after kidney transplantation.

BACKGROUND: Advances in transplantation immunology show that the balance between dendritic cells (DCs) and their subsets can maintain stable immune status in the induction of tolerance after transplantation. The aim of this study was to investigate if DCs and DC subpopulations in recipient peripheral blood are effective diagnostic indicators of acute rejection following kidney transplantation. METHODS: Immunofluorescent flow cytometry was used to classify white blood cells (WBCs), the levels of mononuclear cells and DCs (including the dominant subpopulations, plasmacytoid DC (pDC) and myeloid DC (mDC)) in peripheral blood at 0, 1, 7, and 28 days and 1 year after kidney transplantation in 33 patients. In addition, the blood levels of interleukin-10 (IL-10) and IL-12 were monitored before and after surgery. Fifteen healthy volunteers served as normal controls. Patients were undertaking hemodialysis owing to uremia before surgery. RESULTS: The total number of DCs, pDC, and mDC in peripheral blood and the pDC/mDC ratio were significantly lower in patients than controls (P < 0.05). Peripheral DCs suddenly decreased at the end of day 1, then gradually increased through day 28 but remained below normal levels. After 1 year, levels were higher than before surgery but lower than normal. The mDC levels were higher in patients with acute rejection before and 1 day after surgery (P < 0.005). There was no significant difference in IL-10 and IL-12 levels between patients with and without acute rejection. CONCLUSION: The changes in DCs and DC subpopulations during the acute rejection period may serve as effective markers and referral indices for monitoring the immune state, and predicting rejection and reasonably adjusting immunosuppressants.

Kinetics of DNA-coated sticky particles.

DNA-functionalized particles are promising for complex self-assembly due to their specific controllable thermoreversible interactions. However, there has been little work on the kinetics and the aggregation rate, which depend on the rate of particle encounters and the probability that an encounter results in particles sticking. In this study, we investigate theoretically and experimentally the aggregation times of micron-scale particles as a function of DNA coverage and salt concentration. Our 2-µm colloids accommodate up to 70,000 DNA strands. For full coverage and high salt concentration, the aggregation time is 5 min while for 0.1 coverage and low salt it is 4 days. A simple model using reaction-limited kinetics and experimental oligomer hybridization rates describes the data well. A controlling factor is the Coulomb barrier at the nanometer scale retarding DNA hybridization. Our model allows easy measurements of microscopic hybridization rates from macroscopic aggregation and enables the design of complex self-assembly schemes with controlled kinetics.