Correction: Controlled p-type substitutional doping in large-area monolayer WSe2 crystals grown by chemical vapor deposition.

Correction for 'Controlled p-type substitutional doping in large-area monolayer WSe2 crystals grown by chemical vapor deposition' by Stephen A. Campbell et al., Nanoscale, 2018, 10, 21374-21385.

Controlled p-type substitutional doping in large-area monolayer WSe2 crystals grown by chemical vapor deposition.

Tungsten diselenide (WSe2) is a particularly interesting 2D material due to its p-type conductivity. Here we report a systematic single-step process to optimize crystal size by variation of multiple growth parameters resulting in hexagonal single crystals up to 165 µm wide. We then show that these large single crystals can be controllably in situ doped with the acceptor Niobium (Nb). First principles calculations suggest that substitutional Nb doping of W would yield p-doping with no gap trap states. When used as the active layer of a field effect transistor (FET), doped crystals exhibit conventional p-type behavior, rather than the ambipolar behaviour seen in undoped WSe2 FETs. Nb-doped WSe2 FETs yield a maximum field effect mobility of 116 cm2 V-1 s-1, slightly higher than its undoped counterpart, with an on/off ratio of 106. Doping reduces the contact resistance of WSe2, reaching a minimum value of 0.55 kΩµm in WSe2 FETs. The areal density of holes in Nb-doped WSe2 is approximately double that of undoped WSe2, indicating that Nb doping is working as an effective acceptor. Doping concentration can be controlled over several orders of magnitudes, allowing it to be used to control: FET threshold voltage, FET off-state leakage, and contact resistance.

Anorectal Malformation: Paediatric Problem Presenting in Adult.

This is a case report of 22-year-old girl admitted with abdominal distension, vomiting, and chronic constipation since birth. Abdomen was distended, and perineal examination revealed imperforate anus with vestibular fistula (ARM). So far worldwide very few cases have been reported about anorectal malformation presenting in adulthood, and thus extremely little data is available in the literature about an ideal management of anorectal malformation in adults. In our case in the treatment instead of conventional procedure of posterior sagittal anorectoplasty (PSARP) anal transposition was done and till two years after the definitive treatment during follow-up patient has been doing well with Kelly's score of six. Our experience suggests that anal transposition provides satisfactory outcome in adults presenting late with anorectal malformation.

Dialkyltin(IV)bis(O-tolyl/benzyldithiocarbonate) complexes: spectroscopic, thermogravemetric, antifungal and crystal analysis of n-Bu2Sn(S2COCH2C6H5)2.

Novel compounds of dimethyl- and dibutyltin(IV) with O-tolyl/benzyldithiocarbonates were successfully obtained by the reaction of Me(2)SnC(l2) and n-Bu(2)SnCl(2) with sodium salt of O-tolyl/benzyldithiocarbonates, [o-, m- and p-CH(3)C(6)H(4)OCS(2)Na and C(6)H(5)CH(2)OCS(2)Na], in 1:2 molar ratio in dry toluene. The structure of these newly synthesized complexes has been examined by elemental analysis, FT-IR, multinuclear NMR ((1)H, (13)C and (119)Sn) spectroscopy. The thermal behaviour of the complex (8) has been studied by TGA/DTA analysis. The complex (8), n-Bu2Sn(S2COCH2C6H5)2, crystallizes in the monoclinic space group C2/c, in which tin adopts a distorted octahedron or skew trapezoidal bipyramidal geometry accompanied by two n-butyl chains and the two dithiocarbonate ligands coordinated in an anisobidentate fashion. Antifungal activities against fungus Fusarium sp. of these organotin(IV) derivatives exhibited enhanced activity compared to the free ligands.

Blue electroluminescence from Sb-ZnO/Cd-ZnO/Ga-ZnO heterojunction diode fabricated by dual ion beam sputtering.

p-type Sb-doped ZnO/i-CdZnO/n-type Ga-doped ZnO was grown by dual ion beam sputtering deposition system. Current-voltage characteristics of the heterojunction showed a diode-like rectifying behavior with a turn-on voltage of ~5 V. The diode yielded blue electroluminescence emissions at around 446 nm in forward biased condition at room temperature. The emission intensity increased with the increase of the injection current. A red shifting of the emission peak position was observed with the increment of ambient temperature, indicating a change of band gap of the CdZnO active layer with temperature in low-temperature measurement.

Synthesis, gene silencing, and molecular modeling studies of 4'-C-aminomethyl-2'-O-methyl modified small interfering RNAs.

The linear syntheses of 4'-C-aminomethyl-2'-O-methyl uridine and cytidine nucleoside phosphoramidites were achieved using glucose as the starting material. The modified RNA building blocks were incorporated into small interfering RNAs (siRNAs) by employing solid phase RNA synthesis. Thermal melting studies showed that the modified siRNA duplexes exhibited slightly lower T(m) (∼1 °C/modification) compared to the unmodified duplex. Molecular dynamics simulations revealed that the 4'-C-aminomethyl-2'-O-methyl modified nucleotides adopt South-type conformation in a siRNA duplex, thereby altering the stacking and hydrogen-bonding interactions. These modified siRNAs were also evaluated for their gene silencing efficiency in HeLa cells using a luciferase-based reporter assay. The results indicate that the modifications are well tolerated in various positions of the passenger strand and at the 3' end of the guide strand but are less tolerated in the seed region of the guide strand. The modified siRNAs exhibited prolonged stability in human serum compared to unmodified siRNA. This work has implications for the use of 4'-C-aminomethyl-2'-O-methyl modified nucleotides to overcome some of the challenges associated with the therapeutic utilities of siRNAs.

The first asymmetric organolithium tetramers with simple ether donor bases.

The donor-free trimethylsilylmethyllithium [LiCH(2)SiMe(3)](6) hexameric aggregate is for the first time broken up by simple ether donors such as diethyl ether (Et(2)O) and tert-butylmethyl ether ((t)BuOMe) to give the unprecedented asymmetric tetramers while the chelating dimethoxyethane (DME) gives the expected dimer.

New chelating ligands based on S-organosulfurdiimides: synthesis and single crystal X-ray structures of their lithium complexes.

Three new diimidosulfinates, [TMSCH(2)S(N(t)Bu)(2)Li](2) (1), [2-PyCH(2)S(N(t)Bu)(2)Li](2) (2), and [{PhCH(2)S(N(t)Bu)(2)Li}(2) x THF] (3) (TMS = trimethylsilyl; Py = 2-pyridyl), have been synthesized by the reaction of functionalized alpha-CH(2)-organolithium compounds with bis-tert-butylsulfurdiimide. These new organolithium chelates are characterized by NMR ((1)H, (13)C, (7)Li, and (29)Si) spectroscopy and single-crystal X-ray diffraction analyses. Compounds 1 and 2 crystallize as dimers without donor molecules, whereas one of the lithium atoms in 3 is coordinated by a single THF molecule. The crystal structure of 1 shows significant intramolecular proximity between one methyl group of the trimethylsilyl (TMS) and one lithium atom, which could be described as an electrostatic Li...C interaction. The coordination sphere of each lithium atom in 2 is completed by donation from the nitrogen atom of the pyridyl ring; however, one of the lithium atoms in 3 is coordinated by a THF molecule. In addition, the first mixed sulfurdiimide species containing a diimidosulfinate and a diimidosulfite fragment, [{PhCHS(N(t)Bu)(2)Li(2)(THF)(2)}{MeS(N(t)Bu)(2)Li(THF)}] (4), was isolated by deprotonation of the alpha-CH(2) group in 3. The single-crystal X-ray structure of 4 revealed two different S-bound substituents coexisting in one dimer and two asymmetrically coordinated lithium atoms.