Combining CHA2DS2-VASc score into RCRI for prediction perioperative cardiovascular outcomes in patients undergoing non-cardiac surgery: a retrospective pilot study.

BACKGROUND: Treatment decisions in patients undergoing non-cardiac surgery are based on clinical assessment. The Revised Cardiac Risk Index (RCRI) is pragmatic and widely used but has only moderate discrimination. We aimed to test the efficacy of the CHA2DS2-VASc score and the combination of CHA2DS2-VASc and RCRI to predict perioperative risks for non-cardiac surgery. METHODS: This pre-specified analysis was performed in a retrospective cohort undergoing intra-abdominal surgery in our center from July 1st, 2007 to June 30th, 2008. The possible association between the baseline characteristics (as defined by CHA2DS2-VASc and RCRI) and the primary outcome of composite perioperative cardiac complications (myocardial infarction, cardiac ischemia, heart failure, arrhythmia, stroke, and/or death) and secondary outcomes of individual endpoints were explored using multivariate Logistic regression. The area under the receiver operating characteristic curve (C-statistic) was used for RCRI, CHA2DS2-VASc, and the combined models, and the net reclassification improvement (NRI) was calculated to assess the additional discriminative ability. RESULTS: Of the 1079 patients (age 57.5 ± 17.0 years), 460 (42.6%) were women. A total of 83 patients (7.7%) reached the primary endpoint. Secondary outcomes included 52 cardiac ischemic events, 40 myocardial infarction, 20 atrial fibrillation, 18 heart failure, four strokes, and 30 deaths. The endpoint events increased with the RCRI and CHA2DS2-VASc grade elevated (P < 0.05 for trend). The RCRI showed a moderate predictive ability with a C-statistics of 0.668 (95%CI 0.610-0.725) for the composite cardiac outcome. The C-statistics for the CHA2DS2-VASc was 0.765 (95% CI 0.709-0.820), indicating better performance than the RCRI (p = 0.011). Adding the CHA2DS2-VASc to the RCRI further increased the C-statistic to 0.774(95%CI 0.719-0.829), improved sensitivity, negative predictive value, and enhanced reclassification in reference to RCRI. Similar performance of the combined scores was demonstrated in the analysis of individual secondary endpoints. The best cut-off of a total of 4 scores was suggested for the combined CHA2DS2-VASc and RCRI in the prediction of the perioperative cardiac outcomes. CONCLUSIONS: The CHA2DS2-VASc score significantly enhanced risk assessment for the composite perioperative cardiovascular outcome in comparison to traditional RCRI risk stratification. Incorporation of CHA2DS2-VASc scores into clinical-decision making to improve perioperative management in patients undergoing non-cardiac surgery warrants consideration.

Ge nanodot-mediated densification and crystallization of low-pressure chemical vapor deposited Si3N4 for advanced complementary metal-oxide-semiconductor photonics and electronics applications.

A new phenomenon of highly localized, nanoscale densification and crystallization of silicon-nitride (Si3N4) layers has been observed. A drastic reduction in the thermal budget (temperature and processing time) for local densification and even nanocrystallization of low-pressure chemical vapor deposited amorphous Si3N4 layers is mediated by the presence of Ge, Si, and O interstitials in close proximity to the Si3N4. The enhancement of localized densification and nanocrystallization observed in Si3N4 layers appears to be catalyzed by proximal Ge quantum dots (QDs) 'migrating' through the Si3N4/Si layers and are influenced by the oxidation time and Ge QD size. Implications of the highly localized, nanoscale densification and crystallization of silicon-nitride (Si3N4) layers for photonic and electronic device applications are discussed.

A novel gemcitabine derivative-loaded liposome with great pancreas-targeting ability.

Gemcitabine (Gem) is a standard first-line treatment for pancreatic cancer (PC). However, its chemotherapeutic efficacy is hampered by various limitations such as short half-life, metabolic inactivation, and lack of tumor localizing. We previously synthesized a lipophilic Gem derivative (Gem formyl hexadecyl ester, GemC16) that exhibited improved antitumor activity in vitro. In this study, a target ligand N,N-dimethyl-1,3-propanediamine was conjugated to 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[hydroxyl succinimidyl (polyethylene glycol-2000)] (DSPE-PEG-NHS) to form DSPE-PEG-2N. Then, pancreas-targeting liposomes (2N-LPs) were prepared using the film dispersion-ultrasonic method. GemC16-loaded 2N-LPs displayed near-spherical shapes with an average size distribution of 157.2 nm (polydispersity index (PDI) = 0.201). The encapsulation efficiency of GemC16 was up to 97.3% with a loading capacity of 8.9%. In human PC cell line (BxPC-3) and rat pancreatic acinar cell line (AR42J), cellular uptake of 2N-LPs was significantly enhanced compared with that of unmodified PEG-LPs. 2N-LPs exhibited more potent in vitro cytotoxicity against BxPC-3 and AR42J cell lines than PEG-LPs. After systemic administration in mice, 2N-LPs remarkably increased drug distribution in the pancreas. In an orthotopic tumor mouse model of PC, GemC16-bearing liposomes were more effective in preventing tumor growth than free GemC16. Among these treatments, 2N-LPs showed the best curative effect. Together, 2N-LPs represent a promising nanocarrier to achieve pancreas-targeting drug delivery, and this work would provide new ideas for the chemotherapy of PC.

Very large photoresponsiviy and high photocurrent linearity for Ge-dot/SiO2/SiGe photoMOSFETs under gate modulation.

We report a novel visible-near infrared photoMOSFET containing a self-organized, gate-stacking heterostructure of SiO2/Ge-dot/SiO2/SiGe-channel on Si substrate that is simultaneously fabricated in a single oxidation step. Our typical photoMOSFETs exhibit very large photoresponsivity of 1000-3000A/W at low optical power (< 0.1µW) or large photocurrent gain of 103-108A/A with a wide dynamic power range of at least 6 orders of magnitude (nW-mW) linearity at 400-1250 nm illumination, depending on whether the photoMOSFET operates at VG = + 3- + 4.5V or -1- + 1V. Numerical simulations reveal that photocarrier confinement within the Ge dots and the SiGe channel modifies the oxide field and the surface potential of SiGe, significantly increasing photocurrent and improving linearity.

[Treatment Ideas and Methods for Treating Breast Cancer Guided by Molecular Classification].

The gene types of breast cancer can be classified into three types according to its molecules: Luminal type A, Luminal type B, HER-2-positive type, triple negative type. Authors combined pathological characteristics of breast cancer, biological characteristics, and comprehensive treatment, used syndrome typing based medication, and explored treatment meticulous ideas and methods of "treating the same disease with different methods" as well as "different treatment methods in accordance with patients individually".

Design of multifold Ge/Si/Ge composite quantum-dot heterostructures for visible to near-infrared photodetection.

We demonstrate an effective approach to grow high-quality thin film (>1 µm) of multifold Ge/Si/Ge composite quantum dots (CQDs) stacked heterostructures for near infrared photodetection and optical interconnect applications. An otherwise random, self-assembly of variable-fold Ge/Si CQDs has been grown on Si through the insertion of Si spacer layers to produce micron-scale-thick, stacked Ge/Si CQD layers with desired QD morphology and composition distribution. The high crystalline quality of these multifold Ge CQD heterostructures is evidenced by low dark current density of 3.68 pA/µm2, superior photoresponsivity of 267 and 220 mA/W under 850 and 980 nm illumination, respectively, and very fast temporal response time of 0.24 ns measured on the Ge/Si CQD photodetectors.

A model for predicting the thermal conductivity of SiO2-Ge nanoparticle composites.

We present a simple theoretical model that predicts the thermal conductivity of SiO2 layers with embedded Ge quantum dots (QDs). Overall, the resulting nanoscale architecture comprising the structural relaxation in the SiO2 matrix, deviation in mass density of the QDs compared to the surrounding matrix and local strains associated with the dots are all likely to enhance phonon scattering and thus reduce the thermal conductivity in these systems. We have found that the conductivity reduction can be predicted by the dot-induced local elastic perturbations in SiO2. Our model is able to explain not only this large reduction but also the magnitude and temperature variation of the thermal conductivity with size and density of the dots. Within the error range, the theoretical calculations of the temperature-dependent thermal conductivity in different samples are in close agreement with the experimental measurements. Including the details of the strain fields in oxidized Si nanostructured layers is therefore essential for a better prediction of the heat pathways in on-chip thermoelectric devices and circuits.

[Analysis of perioperative cardiovascular events and related risk factors in patients undergoing intraperitoneal surgery].

OBJECTIVES: To investigate incidence of perioperative cardiovascular events, to analyze related risk factors for the patients undergoing intraperitoneal surgery. METHODS: The data of 1079 patients who underwent intraperitoneal surgery (exclude laparoscope surgery) from July 2007 to June 2008 was reviewed and analyzed. RESULTS: For the patients undergoing intraperitoneal surgery, the incidence of major cardiovascular events was 3.99% (43/1079), all-cause mortality was 1.58% (17/1079). The independent risk factors of major cardiovascular events were age ≥ 60 years, history of coronary heart disease, cardiac insufficiency, arrhythmia, chronic obstructive pulmonary disease, estimated glomerular filtration rate (eGFR) < 60 ml/(min·1.73 m(2)), emergency surgery and duration of surgery > 2.82 h (OR = 2.68 to 5.19, P = 0.001 to 0.031). CONCLUSIONS: The cardiac risk of intraperitoneal surgery is 3.99%. The risk of cardiac complications should be evaluated in elderly patients and those with ischaemic heart disease, chronic obstructive pulmonary disease, and renal disease, more specifically, when emergent or long duration major surgeries are needed.

Determination of exciton binding energy using photocurrent spectroscopy of Ge quantum-dot single-hole transistors under CW pumping.

We reported exciton binding-energy determination using tunneling-current spectroscopy of Germanium (Ge) quantum dot (QD) single-hole transistors (SHTs) operating in the few-hole regime, under 405-1550 nm wavelength (λ) illumination. When the photon energy is smaller than the bandgap energy (1.46 eV) of a 20 nm Ge QD (for instance, λ = 1310 nm and 1550 nm illuminations), there is no change in the peak voltages of tunneling current spectroscopy even when the irradiation power density reaches as high as 10 µW/µm2. In contrast, a considerable shift in the first hole-tunneling current peak towards positive VG is induced (ΔVG ≈ 0.08 V at 0.33 nW/µm2 and 0.15 V at 1.4 nW/µm2) and even additional photocurrent peaks are created at higher positive VG values (ΔVG ≈ 0.2 V at 10 nW/µm2 irradiation) by illumination at λ = 850 nm (where the photon energy matches the bandgap energy of the 20 nm Ge QD). These experimental observations were further strengthened when Ge-QD SHTs were illuminated by λ = 405 nm lasers at much lower optical-power conditions. The newly-photogenerated current peaks are attributed to the contribution of exciton, biexciton, and positive trion complexes. Furthermore, the exciton binding energy can be determined by analyzing the tunneling current spectra.

Ancient Chinese medicine and mechanistic evidence of acupuncture physiology.

Acupuncture has been widely used in China for three millennia as an art of healing. Yet, its physiology is not yet understood. The current interest in acupuncture started in 1971. Soon afterward, extensive research led to the concept of neural signaling with possible involvement of opioid peptides, glutamate, adenosine and identifying responsive parts in the central nervous system. In the last decade scientists began investigating the subject with anatomical and molecular imaging. It was found that mechanical movements of the needle, ignored in the past, appear to be central to the method and intracellular calcium ions may play a pivotal role. In this review, we trace the technique of clinical treatment from the first written record about 2,200 years ago to the modern time. The ancient texts have been used to introduce the concepts of yin, yang, qi, de qi, and meridians, the traditional foundation of acupuncture. We explore the sequence of the physiological process, from the turning of the needle, the mechanical wave activation of calcium ion channel to beta-endorphin secretion. By using modern terminology to re-interpret the ancient texts, we have found that the 2nd century B.C.: physiologists were meticulous investigators and their explanation fits well with the mechanistic model derived from magnetic resonance imaging (MRI) and confocal microscopy. In conclusion, the ancient model appears to have withstood the test of time surprisingly well confirming the popular axiom that the old wine is better than the new.

Physiology and cell biology of acupuncture observed in calcium signaling activated by acoustic shear wave.

This article presents a novel model of acupuncture physiology based on cellular calcium activation by an acoustic shear wave (ASW) generated by the mechanical movement of the needle. An acupuncture needle was driven by a piezoelectric transducer at 100 Hz or below, and the ASW in human calf was imaged by magnetic resonance elastography. At the cell level, the ASW activated intracellular Ca(2+) transients and oscillations in fibroblasts and endothelial, ventricular myocytes and neuronal PC-12 cells along with frequency-amplitude tuning and memory capabilities. Monitoring in vivo mammalian experiments with ASW, enhancement of endorphin in blood plasma and blocking by Gd(3+) were observed; and increased Ca(2+) fluorescence in mouse hind leg muscle was imaged by two-photon microscopy. In contrast with traditional acupuncture models, the signal source is derived from the total acoustic energy. ASW signaling makes use of the anisotropy of elasticity of tissues as its waveguides for transmission and that cell activation is not based on the nervous system.

Nanoscale, catalytically enhanced local oxidation of silicon-containing layers by 'burrowing' Ge quantum dots.

A new phenomenon of highly localized, nanoscale oxidation of silicon-containing layers has been observed. The localized oxidation enhancement observed in both Si and Si(3)N(4) layers appears to be catalyzed by the migration of Ge quantum dots (QDs). The sizes, morphology, and distribution of the Ge QDs are influenced by the oxidation of the Si-bearing layers. A two-step mechanism of dissolution of Si within the Ge QDs prior to oxidation is proposed.

[Clinical evaluation of the efficacy of external therapies of traditional Chinese medicine in treatment of cancer pain].

There lack scientific methods for evaluating the treatment of cancer pain with external therapies of traditional Chinese medicine (TCM). The level of clinical study in this field needs to be improved. The authors assert that when external therapies of TCM are applied to treat cancer pain, different types of cancer pain should be distinguished and treatment should be applied according to such a differentiation. Under this framework scientific evaluation can be conducted. The authors also assert that the findings of randomized, blinded and controlled trials should be given particular attention, and it is necessary to include titration of morphine into clinical trails of external therapies for the treatment of cancer pain, not only complying with the three-ladder principle for treating cancer pain suggested by the World Health Organization, but also not influencing the effect evaluation of external therapies of TCM on cancer pain. Patient diaries recording pain were revised as observation indexes. The primary indicator of efficacy was the pain intensity score and the secondary indicators were the equivalent of morphine and the remission rate of pain. The time to onset, remission duration and comparison of assessment of pain influence can mirror the characteristics of external therapies of TCM on cancer pain.

Germanium Quantum-Dot Array with Self-Aligned Electrodes for Quantum Electronic Devices.

Semiconductor-based quantum registers require scalable quantum-dots (QDs) to be accurately located in close proximity to and independently addressable by external electrodes. Si-based QD qubits have been realized in various lithographically-defined Si/SiGe heterostructures and validated only for milli-Kelvin temperature operation. QD qubits have recently been explored in germanium (Ge) materials systems that are envisaged to operate at higher temperatures, relax lithographic-fabrication requirements, and scale up to large quantum systems. We report the unique scalability and tunability of Ge spherical-shaped QDs that are controllably located, closely coupled between each another, and self-aligned with control electrodes, using a coordinated combination of lithographic patterning and self-assembled growth. The core experimental design is based on the thermal oxidation of poly-SiGe spacer islands located at each sidewall corner or included-angle location of Si3N4/Si-ridges with specially designed fanout structures. Multiple Ge QDs with good tunability in QD sizes and self-aligned electrodes were controllably achieved. Spherical-shaped Ge QDs are closely coupled to each other via coupling barriers of Si3N4 spacer layers/c-Si that are electrically tunable via self-aligned poly-Si or polycide electrodes. Our ability to place size-tunable spherical Ge QDs at any desired location, therefore, offers a large parameter space within which to design novel quantum electronic devices.

Differences in perioperative cardiovascular outcomes in elderly male and female patients undergoing intra-abdominal surgery: a retrospective cohort study.

OBJECTIVE: Perioperative cardiovascular events constitute the majority of complications in noncardiac surgery. Older and female patients have been less investigated. We aimed to evaluate differences in perioperative cardiovascular outcomes by age and sex. METHODS: We enrolled 1079 patients (57.5 ± 17.0 years, 42.6% women) undergoing intra-abdominal surgery from July 2007 to June 2008 and compared occurrence of perioperative cardiac events by age (≥65 vs. <65 years) and sex. Multivariable logistic regression was used to investigate associations between age, sex, and outcomes. RESULTS: Age ≥65 years was associated with perioperative myocardial infarction (MI) (odds ratio [OR] 2.9, 95% confidence interval [CI]: 1.3-6.6) and total cardiovascular events (OR 2.4, 95% CI: 1.3-4.2). Age ≥65 years was associated with higher perioperative MI risks in men (OR 4.7, 95% CI: 1.3-17.6) than in women (OR 3.1, 95% CI: 1.2-8.3). Advanced age was associated with heart failure in women (OR 13.9, 95% CI: 1.7-110.5). Female sex was a risk factor for heart failure in elderly patients (OR 4.2, 95% CI: 1.1-15.7). CONCLUSIONS: Advanced age appeared to be associated with increased perioperative cardiac risk but differed by sex. Tailored strategies should be considered with respect to the patient's sex.

Precise Ge quantum dot placement for quantum tunneling devices.

This study demonstrates the precise placement of Ge quantum dots (QDs) in an SiO2 or Si3N4 matrix in a self-organized manner by thermally oxidizing SiGe in nanostructures. The effectiveness of this method is shown by a variety of geometries including nanotrenches, nanorods and polygonal nanocavities. Modulating the structural geometry and peripheral spacer materials effectively places a single Ge QD in the center of an oxidized SiGe nanostructure or individual QDs at the corners (edges). This study also reports the fabrication of Ge QD single-electron devices that exhibit clear Coulomb staircases and differential conductance oscillations at room temperature.

Enhancement of Antitumor Efficacy of Paclitaxel-Loaded PEGylated Liposomes by N,N-Dimethyl Tertiary Amino Moiety in Pancreatic Cancer.

INTRODUCTION: Pancreatic cancer, or pancreatic duct adenocarcinoma (PDAC), remains one of the most lethal cancers and features insidious onset, highly aggressive behavior and early distant metastasis. The dense fibrotic stroma surrounding tumor cells is thought to be a shield to resist the permeation of chemotherapy drugs in the treatment of PDAC. Thus, we synthesized a pancreas-targeting paclitaxel-loaded PEGylated liposome and investigated its antitumor efficacy in the patient-derived orthotopic xenograft (PDOX) nude mouse models of PDAC. METHODS: The PTX-loaded PEGylated liposomes were prepared by film dispersion-ultrasonic method and modified by an N,N-dimethyl tertiary amino residue. Morphology characteristics of the PTX-loaded liposomes were observed by transmission electron microscope (TEM). The PDOX models of PDAC were established by orthotopic implantation and imaged by a micro positron emission tomography/computed tomography (PET/CT) imaging system. The in vivo distribution and antitumor study were then carried out to observe the pancreas-targeting accumulation and the antitumor efficacy of the proposed PTX liposomes. RESULTS: PTX loaded well into both modified (PTX-Lip2N) and unmodified (PTX-Lip) PEGylated liposomes with spherical shapes and suitable parameters for the endocytosis process. The PDOX nude mouse models were successfully created in which high 18F-FDG intaking regions were observed by micro-PET/CT. In addition to higher cellular uptakes of PTX-Lip2N by the BxPC-3 cells, the proposed nanoparticle had a notable penetrating ability towards PDAC tumor tissues, and consequently, the antitumor ability of PTX-Lip2N was significantly superior to the unmodified PTX-Lip in vivo PDOX models and even more effective than nab-PTX in restraining tumor growth. CONCLUSION: The modified pancreas-targeting PTX-loaded PEGylated liposomes provide a promising platform for the treatment of pancreatic cancer.

The temperature-dependent physical and electrical characteristics of a polymer/RAFT-polymer stabilized nanoparticle system for organic nonvolatile memory.

We have fabricated and investigated organic memory diodes, comprising a single polymer layer and Au nanoparticles stabilized by the same polymer material utilizing a reversible addition-fragmentation transfer technique to suppress phase separation. The organic memory diodes exhibit well reproducible and prominent current bistability and good charge retention characteristics free from phase separation issues. Nondestructive spectroscopic ellipsometry is used to characterize the physical properties of the polymer/nanoparticle composites, such as the polymer's effective dielectric function/layer thickness and the Au nanoparticle's effective volume fraction, which are important parameters for gaining insightful information on charge transport in this system. Temperature-dependent analysis of the read/write current behaviors suggests that charge transport in such a polymer/Au nanoparticle composite is dominated by carrier hopping via shallow-level traps at the high field regime.

Enhancing the Seebeck effect in Ge/Si through the combination of interfacial design features.

Due to their inherent physical properties, thin-film Si/SiGe heterostructures have specific thermal management applications in advanced integrated circuits and this in turn is essential not only to prevent a high local temperature and overheat inside the circuit, but also generate electricity through the Seebeck effect. Here, we were able to enhance the Seebeck effect in the germanium composite quantum dots (CQDs) embedded in silicon by increasing the number of thin silicon layers inside the dot (multi-fold CQD material). The Seebeck effect in the CQD structures and multi-layer boron atomic layer-doped SiGe epitaxial films was studied experimentally at temperatures in the range from 50 to 300 K and detailed calculations for the Seebeck coefficient employing different scattering mechanisms were made. Our results show that the Seebeck coefficient is enhanced up to ≈40% in a 3-fold CQD material with respect to 2-fold Ge/Si CQDs. This enhancement was precisely modeled by taking into account the scattering of phonons by inner boundaries and the carrier filtering by the CQD inclusions. Our model is also able to reproduce the observed temperature dependence of the Seebeck coefficient in the B atomic layer-doped SiGe fairly well. We expect that the phonon scattering techniques developed here could significantly improve the thermoelectric performance of Ge/Si materials through further optimization of the layer stacks inside the quantum dot and of the dopant concentrations.

Tunable diameter and spacing of double Ge quantum dots using highly-controllable spacers and selective oxidation of SiGe.

We report the novel tunability of the diameters and spacings of paired Ge double quantum dots (DQDs) using nano-spacer technology in combination with selective oxidation of Si0.85Ge0.15 at high temperature. Pairs of spherical-shaped Ge QDs were formed by the selective oxidation of poly-SiGe spacer islands at each sidewall corner of the nano-patterned Si3N4/poly-Si ridges. The diameters of the Ge spherical QDs are essentially determined by geometrical conditions (height, width, and length) of the nano-patterned spacer islands of poly-SiGe, which are tunable by adjusting the process times of deposition and etch back for poly-SiGe spacer layers in combination with the exposure dose of electron-beam lithography. Most importantly, the separations between the Ge DQDs are controllable by adjusting the widths of the poly-Si/Si3N4 ridges and the thermal oxidation times. Our self-organization and self-alignment approach achieved high symmetry within the Ge DQDs in terms of the individual QD diameters as well as the coupling barriers between the QDs and external electrodes in close proximity.