Improved 2-pyridyl reductive homocoupling reaction using biorenewable solvent Cyrene™ (dihydrolevoglucosenone).

The synthesis of 5,5'-bis(trifluoromethyl)-2,2'-bipyridine using 2-bromo-5-(trifluoromethyl) pyridine was achieved at 50 °C using palladium acetate, tetrabutylammonium iodide (TBAI), potassium carbonate, and isopropanol in Cyrene™ (dihydrolevoglucosenone), a bio-renewable "green" solvent formed by a two-step process from cellulose. Improvements were achieved with 50% of γ-valerolactone (GVL) in Cyrene™ resulting in a 95% yield and 99% product purity without the use of column chromatography or recrystallization. At 80 °C, the reaction was completed within 1 h. Full conversion with 1 mol% instead of 15 mol% of palladium acetate was observed within 10 h. We showed that the formed 2,2'-bipyridine product significantly accelerated the reaction probably due to the stabilization of the catalytic species. The addition of TBAI was essential for the rapid homocoupling, however, 20 mol% of TBAI was sufficient to reach full conversion of 2-bromo-5-(trifluoromethyl) pyridine within 6 h at 80 °C. Another improvement was observed with the substitution of isopropanol by 1,4-butanediol achieving full conversion within 6 h. 2-Bromopyridines with electron withdrawing substituents in the 6, 5, 4 ring position reacted under these conditions. 2-Bromopyridines with an electron donating substituent reacted slower. Overall, we demonstrated that the 50% GVL in Cyrene™ blend is a superior "green" and less toxic alternative to dimethylformamide for the reductive homocoupling reaction. Using a quantitative scoring for twelve principles of green chemistry (DOZN™), we found significant improvements that were mediated by higher yield (atom economy), shorter heating time and lower reaction temperature (energy efficiency), safer solvent (hazardous chemical synthesis), and safer chemistry (accident prevention).

Molybdenum target mammography-based prediction model for metastasis of axillary sentinel lymph node in early-stage breast cancer.

Sentinel lymph node (SLN) status is closely related to axillary lymph node metastasis in breast cancer. However, SLN biopsy has certain limitations due to invasiveness and diagnostic efficiency. This study aimed to develop a model to predict the risk of axillary SLN metastasis in early-stage breast cancer based on mammography, a noninvasive, cost-effective, and potential complementary way. Herein, 649 patients with early-stage breast cancer (cT1-T2) who received SLN biopsy were assigned to the training cohort (n = 487) and the validation cohort (n = 162). A prediction model based on specific characteristics of tumor mass in mammography was developed and validated with R software. The performance of model was evaluated by receiver operating characteristic curve, calibration plot, and decision curve analysis. Tumor margins, spicular structures, calcification, and tumor size were independent predictors of SLN metastasis (all P < .05). A nomogram showed a satisfactory performance with an AUC of 0.829 (95% CI = 0.792-0.865) in the training cohort and an AUC of 0.825 (95% CI = 0.763-0.888) in validation cohort. The consistency between model-predicted results and actual observations showed great Hosmer-Lemeshow goodness-of-fit (P = .104). Patients could benefit from clinical decisions guided by the present model within the threshold probabilities of 6% to 84%. The prediction model for axillary SLN metastasis showed satisfactory discrimination, calibration abilities, and wide clinical practicability. These findings suggest that our prediction model based on mammography characteristics is a reliable tool for predicting SLN metastasis in patients with early-stage breast cancer.

A randomized, controlled single, and multiple ascending dose trial of the safety, pharmacokinetics and pharmacodynamics of SN1011 in healthy subjects.

The purpose of this study was to investigate the safety, tolerability, pharmacokinetics, and pharmacodynamics of SN1011, a novel Bruton tyrosine kinase (BTK) inhibitor, and food effects in healthy subjects. In this phase I trial, subjects received single ascending doses (SADs) of SN1011 (100 to 800 mg), multiple ascending doses (MADs) of SN1011 (200 to 600 mg), or placebo q.d. Additionally, 12 subjects randomly received a single dose of SN1011 600 mg under fasting states and then fed states, vice versa. Safety was assessed per Common Terminology Criteria for Adverse Events version 5.0. Pharmacokinetic parameters were calculated by noncompartmental analysis and BTK receptor occupancy in peripheral blood monocytes was determined. Seventy-one healthy subjects were dosed in five SAD cohorts, three MAD cohorts, and one food effect cohort, with 57 receiving SN1011 and 14 receiving placebo. No serious adverse events (AEs) were reported. There was no correlation between AE occurrences and SN1011 exposure. The three most frequent AEs with SN1011 were increased blood triglycerides, decreased neutrophil count, and decreased leucocyte count. SN1011 exhibited a dose-proportional increase in maximum plasma concentration and area under the time concentration curve following single and multiple dose administrations, with an accumulation ratio of 1.5 to 2.2 after multiple dose administrations. No difference in SN1011 exposure was observed between fed states. BTK receptor occupancy remained above 83% over 24 h after single administration and remained above 80% for the MAD groups for 10 days of continuous q.d. administration. SN1011 was well-tolerated and safe after single or multiple exposures to healthy subjects, supporting further clinical development of SN1011 for treatment of autoimmune diseases.

Correlation between PRDX2 and spermatogenesis under oxidative stress.

BACKGROUND: Obesity is one of the world's diseases that endanger human health, causing systemic inflammation caused by excessive reactive oxygen damage. An increase in the proportion of obese people with reduced sperm motility has been reported. But the mechanism behind it remains unclear. Peroxiredoxin 2 (PRDX2) is a member of the peroxidase family that effectively removes hydrogen peroxide. This study is to clarify the expression of PRDX2 in the testes of obese mice and lay a foundation for further exploration of the regulatory and protective effects of PRDX2 on spermatogenesis. METHOD: A model of high-fat-induced obesity in animals was constructed, and the expression of PRDX2 in the testes of the two groups was detected by immunohistochemistry, western blotting, immunofluorescence and other techniques. Hydrogen peroxide (H2O2) and cholesterol were co-cultured in testicular support cells for 48 h to observe the expression of PRDX2. RESULT: PRDX2 expression was reduced in the testes of the obese group, and immunohistochemistry showed that it was mainly localized to supporting cells. H2O2 inhibits the expression of PRDX2 in Sertoli cells, and high cholesterol upregulates the expression of PRDX2 in Sertoli cells. CONCLUSION: PRDX2 has some antioxidant properties against changes in the testicular environment caused by HFD. And under short-term oxidative stress to enhance its antioxidant capacity. PRDX2 may be involved in maintaining the oxidative balance of the spermatogenesis environment.

Enhanced cell trapping throughput using DC-biased AC electric field in a dielectrophoresis-based fluidic device with densely packed silica beads.

This paper presents the use of DC-biased AC electric field for enhancing cell trapping throughput in an insulator-based dielectrophoretic (iDEP) fluidic device with densely packed silica beads. Cell suspension is carried through the iDEP device by a pressure-driven flow. Under an applied DC-biased AC electric field, DEP trapping force is produced as a result of non-uniform electric field induced by the gap of electrically insulating silica beads packed between two mesh electrodes that allow both fluid and cells to pass through. While the AC component is mainly to control the magnitude of DEP trapping force, the DC component generates local electroosmotic (EO) flow in the cavity between the beads and the EO flow can be set to move along or against the main pressure-driven flow. Our experimental and simulation results show that desirable trapping is achieved when the EO flow direction is along (not against) the main flow direction. Using our proposed DC-biased AC field, the device can enhance the trapping throughput (in terms of the flowrate of cell suspension) up to five times while yielding almost the same cell capture rates as compared to the pure AC field case. Additionally, the device was demonstrated to selectively trap dead yeast cells from a mixture of flowing live and dead yeast cells.

Postoperative recurrence analysis of breast cancer patients based on clinical serum markers using discriminant methods.

BACKGROUND: Breast cancer is a common gynecological malignant tumor and currently its clinical diagnosis mainly depends on methods of iconography and measurement of serum level. OBJECTIVE: To analyze correlation between serum index levels and prognosis of patients with breast cancer in one week and six months after operation, and to establish support vector machine (SVM) model to evaluate its effectiveness. METHODS: One hundred sixty eight patients diagnosed with breast cancer at Affiliated Cancer Hospital of Zhengzhou University were collected, 46 of which did palindromia while other 122 didn't six months after operation. Serum CA153, CA125 and CEA levels of different periods in two groups were analyzed from their differences. Through receiver operating characteristic (ROC) curve analysis, their diagnostic threshold values were calculated, at the same time, SVM model was built. RESULTS: There was a significant difference between serum index levels of recurrence group and non-recurrence group in one week and six months after operation (P< 0.05); SVM model was established with an accuracy of 96.67% (29/30), a sensitivity of 90% (9/10) and a specificity of 100% (20/20). CONCLUSIONS: Serum CAl53, CEA and CA125 levels after operation have certain instructional significance for prognosis of breast cancer patients, and the established SVM model has high clinical application value.

Modulation of electronic couplings within Ru2-polyyne frameworks.

Dimers of [Ru(2)(Xap)(4)] bridged by 1,3,5-hexatriyn-diyl (Xap are 2-anilinopyridinate and its aniline substituted derivatives), [Ru(2)(Xap)(4)](2)(µ-C(6)) (1), were prepared. Compounds 1 reacted with 1 equiv of tetracyanoethene (TCNE) to yield the cyclo-addition/insertion products [Ru(2)(Xap)(4)](2){µ-C≡CC(C(CN)(2))-C(C(CN)(2))C≡C} (2) and 1 equiv of Co(2)(dppm)(CO)(6) to yield the η(2)-Co(2) adducts to the middle C≡C bond, [Ru(2)(Xap)(4)](2)(µ-C(6))(Co(2)(dppm)(CO)(4)) (3). Voltammetric and spectroelectrochemical studies revealed that (i) two Ru(2) termini in 1 are sufficiently coupled with the monoanion (1(-)) as a Robin-Day class II/III mixed valence species; (ii) the coupling between two Ru(2) is still significant but somewhat weakened in 3; and (iii) the coupling between two Ru(2) is completely removed by the insertion of TCNE in 2. The attenuation of electronic couplings in 2 and 3 was further explored with both the X-ray diffraction study of representative compounds and spin-unrestricted DFT calculations.

[One case of correlation between the human herpesvirus 7 DNA load and the hemo hagocytic syndrome].

OBJECTIVE: To research the relationship between human herpesvirus 7 (HHV-7) viral Load and the etiopathogenisis of hemophagocytic syndrome, in order to provide evidence for the clinical diagnosis of hemophagocytic syndrome and anti-virus therapy. METHODS: Peripheral blood of patient with hemophagocytic syndrome during different treatment periods, extracted DNA, Syntheticed the primers of HHV-7, gene sequence of PCR amplified fragments detected, determined HHV-7 viral Load by Real-time fluorescent quantitative PCR and the ferritin concentration in peripheral blood detected by chemiluminescence. RESULT: The sequence result indicated that PCR amplified fragment was a part of HHV-7 gene, the ferritin concentration viried with the load of HHV-7. CONCLUSION: The occurrence of hemophagocytic syndrome is connetted with the load of HHV-7.

A self-contained polymeric cartridge for automated biological sample preparation.

Sample preparation is one of the most crucial processes for nucleic acids based disease diagnosis. Several steps are required for nucleic acids extraction, impurity washes, and DNA/RNA elution. Careful sample preparation is vital to the obtaining of reliable diagnosis, especially with low copies of pathogens and cells. This paper describes a low-cost, disposable lab cartridge for automatic sample preparation, which is capable of handling flexible sample volumes of 10 µl to 1 ml. This plastic cartridge contains all the necessary reagents for pathogen and cell lysis, DNA/RNA extraction, impurity washes, DNA/RNA elution and waste processing in a completely sealed cartridge. The entire sample preparation processes are automatically conducted within the cartridge on a desktop unit using a pneumatic fluid manipulation approach. Reagents transportation is achieved with a combination of push and pull forces (with compressed air and vacuum, respectively), which are connected to the pneumatic inlets at the bottom of the cartridge. These pneumatic forces are regulated by pinch valve manifold and two pneumatic syringe pumps within the desktop unit. The performance of this pneumatic reagent delivery method was examined. We have demonstrated the capability of the on-cartridge RNA extraction and cancer-specific gene amplification from 10 copies of MCF-7 breast cancer cells. The on-cartridge DNA recovery efficiency was 54-63%, which was comparable to or better than the conventional manual approach using silica spin column. The lab cartridge would be suitable for integration with lab-chip real-time polymerase chain reaction devices in providing a portable system for decentralized disease diagnosis.

A self-contained all-in-one cartridge for sample preparation and real-time PCR in rapid influenza diagnosis.

Herein we present a fully automated system with pseudo-multiplexing capability for rapid infectious disease diagnosis. The all-in-one system was comprised of a polymer cartridge, a miniaturized thermal cycler, 1-color, 3-chamber fluorescence detectors for real-time reverse transcription polymerase chain reaction (RRT-PCR), and a pneumatic fluidic delivery unit consisting of two pinch-valve manifolds and two pneumatic pumps. The disposable, self-contained cartridge held all the necessary reagents for viral RNA purification and reverse transcription polymerase chain reaction (RT-PCR) detection, which took place all within the completely sealed cartridge. The operator only needed to pipette the patient's sample with lysis buffer into the cartridge, and the system would automatically perform the entire sample preparation and diagnosis within 2.5 h. We have successfully employed this system for seasonal influenza A H1N1 typing and sub-typing, obtaining comparable sensitivity as the experiments conducted using manual RNA extraction and commercial thermal cycler. A minimum detectable virus loading of 100 copies per µl has been determined by serial dilution experiments. This all-in-one desktop system would be suitable for decentralized disease diagnosis at immigration check points and outpatient clinics, and would not require highly skilled operators.

Separation of model mixtures of epsilon-globin positive fetal nucleated red blood cells and anucleate erythrocytes using a microfluidic device.

Microfluidic devices are capable of separating microparticles and cells. We developed and tested the efficiency of silicon cross-flow microfilters for the separation of primitive fetal nucleated red blood cells (FNRBCs) and adult anucleate red blood cell (AARBCs) from model mixtures. Stepwise improvements over three generations of device design resulted in an increasing trend in the recovery of FNRBCs. We obtained a recovery of FNRBCs (74.0+/-6.3%, p<0.05, n=5) using the third generation device, with a depletion of 46.5+/-3.2% AARBCs from the cell mixture. The purity of FNRBCs in the enriched fraction was enhanced by a factor of 1.7-fold.

Dielectrophoretic field-flow method for separating particle populations in a chip with asymmetric electrodes.

This paper presents a field-flow method for separating particle populations in a dielectrophoretic (DEP) chip with asymmetric electrodes under continuous flow. The structure of the DEP device (with one thick electrode that defines the walls of the microfluidic channel and one thin electrode), as well as the fabrication and characterization of the device, was previously described. A characteristic of this structure is that it generates an increased gradient of electric field in the vertical plane that can levitate the particles experiencing negative DEP. The separation method consists of trapping one population to the bottom of the microfluidic channel using positive DEP, while the other population that exhibits negative DEP is levitated and flowed out. Viable and nonviable yeast cells were used for testing of the separation method.

[The correlation between the polyomavirus DNA load and the dose of immunosuppressant].

OBJECTIVE: To explore the correlation between the polyomavirus DNA load and the dose of immunosuppressant in patients with allogene bone marrow transplantation (allo-BMT) for preventing the development of post-transplantational hemorrhagic cystitis. METHODS: Serial blood and urine samples from 122 cases of allo-BMT recipients were obtained and DNA was extracted from urine samples. Polyomavirus DNA-specific probe was synthesized and Fluorescence quantitative polymerase chain reaction was used for detecting the polyomavirus DNA loads and Fluorescence polarization immunoassay (FPIA) was performed for determining the dose of immunosuppressant Cyclosporin A (CsA) in blood. RESULTS: The altered polyomavirus DNA load in urine was followed by concentration of CsA in blood. When the concentration of CsA in blood was higher than 86-105 ng/ml, the positive rate of polyomavirus DNA load was significantly increased and both presented the linable correlation. CONCLUSION: In immunosuppression condition, polyomavirus DNA load correlated to the dose of immunosuppressant, which increased the risk of post-transplantational hemorrhagic cystitis.

Bis-alkynyl diruthenium compounds with built-in electronic asymmetry: toward an organometallic Aviram-Ratner diode.

Conditions to prepare trans-[Ru2(dmba)4(C[triple chemical bond]CAr)2] from [Ru2(dmba)4(NO(3))2] (DMBA=N,N'-dimethylbenzamidinate) and HC[triple chemical bond]CAr were optimized; Et2NH was found to be the most effective among a number of weak bases in facilitating the product formation. Furthermore, a series of unsymmetric trans-[(ArC[triple chemical bond]C)Ru(2)(dmba)4(C[triple chemical bond]CAr')] compounds were prepared under optimized conditions, in which one or both of Ar and Ar' are donor (NMe2)-/acceptor (NO(2))-substituted phenyls. While the X-ray crystallographic studies revealed a minimal structural effect upon donor/acceptor substitution, voltammetric measurements indicated a significant influence of substituents on the energy level of frontier orbitals. In particular, placing a donor and an acceptor on the opposite ends of trans-[(ArC[triple chemical bond]C)Ru2(dmba)4(C[triple chemical bond]CAr')] moiety results in an energetic alignment of frontier orbitals that favors a directional electron flow, a necessary condition for unimolecular rectification.

A 3-D dielectrophoretic filter chip.

The paper presents a 3-D filter chip employing both mechanical and dielectrophoretic (DEP) filtration, and its corresponding microfabrication techniques. The device structure is similar to a classical capacitor: two planar electrodes, made from a stainless steel mesh, and bonded on both sides of a glass frame filled with round silica beads. The solution with the suspension of particles flows through both the mesh-electrodes and silica beads filter. The top stainless steel mesh (with openings of 60 mum and wires of 30 mum-thickness) provides the first stage of filtration based on mechanical trapping. A second level of filtration is based on DEP by using the nonuniformities of the electric field generated in the capacitor due to the nonuniformities of the dielectric medium. The filter can work also with DC and AC electric fields. The device was tested with yeast cells (Saccharomyces cerevisae) and achieved a maximal trapping efficiency of 75% at an applied AC voltage of 200 V and a flow rate of 0.1 mL/min, from an initial concentration of cells of 5 x 10(5) cells/mL. When the applied frequency was varieted in the range between 20 and 200 kHz, a minimal value of capture efficiency (3%) was notticed at 50 kHz, when yeast cells exhibit negative DEP and the cells are repelled in the space between the beads.

Suzuki coupling at the periphery of diruthenium coordination and organometallic compounds.

A series of diruthenium compounds, Ru2(DArF)3(L")Cl (2), where the auxiliary ligand DArF is DmAniF or D(3,5-Cl2Ph)F and L" is one of the diarylformamidinate ligands containing at least one biphenyl, were prepared from Suzuki reactions between Ru2(DArF)3(L')Cl (1), where L' is (4-I-Ph)NC(H)NPh (N-(4-iodophenyl)-N'-phenylformamidinate) or D(4-I-Ph)F (N,N'-di(4-iodophenyl)formamidinate), and ArB(OH)2 (Ar = Ph and 4-CH3C(O)Ph) in satisfactory yields. Alkynylation of the type 2 compounds with LiCCPh yielded the alkynyl derivatives Ru2(DArF)3(L")(CCPh) (3). Alternatively, type 3 compounds can be prepared from the Suzuki coupling reaction between Ru2(DArF)3(L')(C2Ph) and ArB(OH)2. A structural comparison between the type 1 and 2 compounds revealed minimal changes in the coordination sphere of Ru2 core. Cyclic voltammograms of Suzuki derivatives resemble those of the parent compounds, indicating the retention of the electrophore characteristic of diruthenium species upon peripheral modification.

Strong electronic couplings between ferrocenyl centers mediated by bis-ethynyl/butadiynyl diruthenium bridges.

A series of trans-(FcC(2n))Ru(2)(Y-DMBA)(4)(C(2m)Fc) with n, m = 1 and 2 and Y-DMBA as N,N'-dimethylbenzamidinate or N,N'-dimethyl-(3-methoxy)benzamidinate have been synthesized and characterized. The intramolecular Fc...Fc distances, established through single-crystal X-ray diffraction studies, range from 11.6 to 16.6 A. Results from both voltammetric and spectroelectrochemical studies indicate that the (-C(2n))Ru(2)(Y-DMBA)(4)(C(2m-) fragments are among the most efficient mediators of intramolecular hole transfer. Density-functional calculations offer both the insight on the ground-state electronic properties and unambiguous assignment for the observed electronic absorptions.

Diosmium(III) compounds supported by 2-anilinopyridinate and novel alkynyl derivatives.

The reaction between Os(2)(OAc)(4)Cl(2) and Hap (Hap is 2-anilinopyridine) under prolonged refluxing conditions resulted in an Os(III)(2) compound, Os(2)(ap)(4)Cl(2) (1), that can be crystallized as either the cis-(2,2) isomer from a CH(3)OH-CH(2)Cl(2) solution or the (3,1) isomer from a hexanes-CH(2)Cl(2) solution. Compound 1 undergoes facile reactions with LiC(2)Y to yield a series of Os(2)(ap)(4)(C(2)Y)(2) compounds with Y as Ph (2), ferrocenyl (3), SiMe(3) (4), and C(2)SiMe(3) (5). X-ray diffraction study of compound 2 reveals solvent-dependent isomerism similar to that of the parent compound 1. Compound 1 has Os-Os distances of 2.3937(8) and 2.3913(8) Angstroms for the cis-(2,2) and (3,1) isomers, respectively, and is paramagnetic (S = 1). Both the ethynyl derivatives 2-4 and butadiynyl derivative 5 are diamagnetic and have Os-Os distances of 2.456(1), 2.471(1), and 2.481(1) Angstroms for the cis-(2,2) and (3,1) isomers of 2 and (3,1) isomer of 4, respectively. Compounds 1-5 exhibit multiple one-electron redox couples in their cyclic voltammograms, including a reversible Os(2)(8+/7+) couple for 2. Resonance Raman spectra of both compounds 1 and 2 are reported.

Ru2(ap)4(sigma-oligo(phenyleneethynyl)) molecular wires: synthesis and electronic characterization.

Reported in this contribution are the synthesis, characterization, and charge transport properties of wire-like Ru2(ap)4(OPEn), where ap is 2-anilinopyridinate and OPE is -(CCC6H4)nSCH2CH2SiMe3 with n = 1 (1) and 2 (2). Scanning tunneling microscopy (STM) measurements of compound 2 inserted into a SAM of C11 thiol reveal that molecule 2 exhibits (i) the stochastic switching characteristic of wire molecules embedded in insulating SAMs and (ii) higher conductivity than the C11 thiol SAM. More importantly, analysis of the molecular electronic decay constant (beta) exhibits a decrease of at least 15% as compared to purely organic molecular analogues. Hence, the transport characteristics of molecules can be significantly improved for nanoscale electronics through the incorporation of a Ru2 fragment into conjugated backbone.