Electrical Kinetic Model of a Hydroxylated Graphene FET Gas Sensor.

Graphene transistor sensors, with advantages such as facile surface functionalization and high sensitivity, have gained extensive research interest in gas detection applications. This study fabricated back-gated graphene transistors and employed a hydroxylation scheme for the surface functionalization of graphene. On the basis of the interaction mechanisms between gas molecules and graphene's electrical properties, a compact electrical kinetics model considering the gas-solid surface reaction of graphene transistors is proposed. The model can accurately predict the electrical kinetic performance and can be used to optimize sensor characteristics. The bias condition of a higher response can be rapidly determined. In addition, the density of hydroxyl groups on graphene is revealed to be the direction of improvement and a key factor of response. Hence, the gas detection capacity of sensors with varying densities of hydroxyl groups was assessed concerning ammonia gas, and design technology co-optimization (DTCO) is realized. Measurement results show that the sensor with 70 s of hydroxylation time has a 7.7% response under 22 ppm ammonia gas.

Efficacy and Safety of Niraparib as First-Line Maintenance Treatment for Patients with Advanced Ovarian Cancer: Real-World Data from a Multicenter Study in China.

BACKGROUND: Poly (ADP-ribose) polymerase (PARP) inhibitors are a new maintenance therapy option for patients with ovarian cancer (OC). OBJECTIVE: To evaluate the efficacy and influencing factors of the novel PARP inhibitor niraparib for maintenance treatment of Chinese patients with advanced OC. PATIENTS AND METHODS: In this retrospective multicenter real-world study patients with advanced OC from 15 hospitals throughout China were enrolled. The primary endpoint was progression-free survival (PFS) and the secondary endpoints included the time to treatment discontinuation and safety. Least Absolute Shrinkage and Selection Operator (LASSO) regression was used to identify possible risk factors for PFS, after which a prediction model was established to evaluate the likelihood of achieving an 18-month PFS. The relationship between the dose of niraparib and PFS was also evaluated. RESULTS: The PFS rates of 199 patients at 6, 12, 18, 24, and 30 months were 87.4%, 75.9%, 63.6%, 56.1%, and 51.8%, respectively. LASSO regression model revealed that only age < 65 years (P = 0.011), BRCA mutations (P < 0.001), and R0 status after cytoreductive surgery (P = 0.01) were significant factors associated with prolonged PFS times. Based on the LASSO logistic regression analysis, a clinical prediction formula was developed: - 2.412 + 1.396Age≥65yr + 2.374BRCAwt + 1.387R1 + 0.793Interval≥12w + 0.178BMI>24kg/m2 which yielded a cut-off value of 0.091, an area under the curve (AUC) of 0.839 (0.763-0.916), a sensitivity of 94.3%, and an accuracy of 78.5%. A nomogram was then built to visualize the results. The major treatment-emergent adverse events of ≥ grade 3 included a platelet count decrease (19.1%), white blood cell count decrease (15.1%), neutrophil count decrease (13.1%), and anemia (18.6%). The 18-month PFS rates in patients treated with 200 mg niraparib were somewhat higher than in patients treated with 100 mg after 3-months of therapy. CONCLUSIONS: For Chinese OC patients, niraparib, particularly at a 200 mg individual starting dose, was an effective therapy with easily manageable safety.

Maintenance therapy with poly (ADP-ribose) polymerase inhibitors is a new option for patients with ovarian cancer (OC) after they have received platinum-based chemotherapy to reduce the recurrence or relapse rates, but it remains unclear whether there are any changes in efficacy and safety when different starting doses of niraparib are administrated to Chinese patients, who typically have a bodyweight < 77 kg. We found that niraparib exhibited satisfactory efficacy with tolerable safety during maintenance therapy for advanced OC whether administered at 100 mg or 200 mg doses. We believe these regimens can serve as a valuable addition to the previous results of randomized controlled trials.

Rubochingosides A - J, labdane-type diterpene glycosides from leaves of Rubus chingii.

Ten previously undescribed labdane-type triterpenoids, rubochingosides A - J (1-10), were isolated from the leaves of Rubus chingii Hu. Their structures were elucidated by spectroscopic and chemical methods. The cytotoxicity of all isolated compounds was tested against five human tumor cell lines (Bel-7402, Caski, BGC-823, A2780, and HCT-116). Among them, compounds 4 and 8 showed cytotoxic activities against Bel-7402 and A2780 cells with IC50 values of 10.43 ± 0.51 and 29.03 ± 2.94 µM, respectively; Compound 8 exhibited cytotoxic activities against Bel-7402 and HCT-116 cells with IC50 values of 17.78 ± 1.54 and 26.23 ± 6.14 µM, respectively.

Double-receptor sandwich supramolecule sensing method for the determination of ATP based on uranyl-salophen complex and aptamer.

In this study, we report a double-receptor sandwich supramolecule sensing method for the determination of adenosine triphosphate (ATP). One receptor is a uranyl-salophen complex which can bind the triphosphate group in ATP selectively, and another is an anti-adenosine aptamer which is a single-stranded oligonucleotide and can recognize the adenosine group in ATP specifically. The uranyl-salophen complex was immobilized on the surface of amino-silica gel particles and used as the solid phase receptor of ATP. The anti-adenosine aptamer was labeled with a fluorescent group and used as the labeled receptor of ATP. In the procedure of ATP detection, ATP was first combined with the solid phase receptor and then conjugated with the labeled receptor to form a sandwich-type supramolecule. The conditions of fabricating solid phase receptor and the influence of manifold variables on the determination were studied. The experimental results demonstrate that the method has a number of advantages such as high selectivity, high sensitivity, good stability and low cost. Under optimal conditions, the linear range for detection of ATP is 0.2-5.0 nmol/mL with a detection limit of 0.037 nmol/mL. The proposed method was successfully applied for the determination of ATP in real samples with the recoveries of 96.8-103.3%.

4-Iodo-anilinium perchlorate 18-crown-6 clathrate.

In the title compound, C(6)H(7)IN(+)·ClO(4) (-)·C(12)H(24)O(6), the proton-ated 4-iodo-anilinium cation inter-acts with the 18-crown-6 through three N-H⋯O hydrogen bonds, forming a rotator-stator-like structure. The cation, anion and 18-crown-6 mol-ecule all have crystallographically imposed mirror symmetry.