Structural, vibrational and thermal studies of a new nonlinear optical material: L-asparagine-L-tartaric acid

Crystals of a new nonlinear optical (NLO) material, viz., L-asparagine-L-tartaric acid (LALT) (1) were grown by slow evaporation of an aqueous solution containing equimolar concentrations of L-asparagine and L-tartaric acid. The structure of the title compound which crystallizes in the non-centrosymmetric monoclinic space group P2(1) consists of a molecule of L-asparagine and a molecule of free l-tartaric acid both of which are interlinked by three varieties of H-bonding interactions namely O-H···O, N-H···O and C-H···O. The UV-Vis-NIR spectrum of 1 reveals its transparent nature while the vibrational spectra confirm the presence of the functional groups in 1. The thermal stability and second harmonic generation (SHG) conversion efficiency of 1 were investigated.

5′′-(4-Chlorobenzylidene)-4′-(4-chlorophenyl)-5-fluoro-1′,1′′-dimethylindoline-3-spiro-2′-pyrrolidine-3′-spiro-3′′-piperidine-2,4′′-dione

The piperidine ring of the title compound, C₃₀H₂₆Cl₂FN₃O₂, adopts a twisted chair conformation. The pyrrolidine ring has a twisted envelope structure with the N atom at the flap [displaced by 0.592 (3) Å]. The fluoro­oxindole, chloro­phenyl and chloro­benzyl­idene groups are planar with r.m.s. deviations of 0.0348, 0.0048 and 0.0048 Å, respectively. The structure is stabilized by inter­molecular N—H⋯O hydrogen bonds.

Prediction of lymph node metastases by preoperative nuclear morphometry in oral squamous cell carcinoma: a comparative image analysis study

CONTEXT

Prediction of metastases of oral squamous cell carcinoma (OSCC) using incisional biopsy.

AIMS

To assess the efficacy of nuclear morphometry in predicting the nodal metastases of OSCC and to compare manual and computer-based image analyses.

MATERIALS AND METHODS

Sixteen cases of moderately differentiated squamous cell carcinoma (8 with metastasized lymph nodes and 8 node-negative cases) were examined using manual and computer-based image analyses. Nuclear area, perimeter, circular rate, larger to shorter axis ratio, and coefficient of variance of nuclear area (NACV) were calculated from 100 nuclei of the processed incisional biopsy specimen.

STATISTICAL ANALYSIS

The parameters were compared between the node positive and negative cases using Student's t test and with the level of lymph node involved using ANOVA test and Bonferroni's post hoc assessment. Manual and computer-based image analyses were compared by Spearman's correlation.

RESULTS

A significant variation between the node positive and negative groups was observed with respect to circular rate (P = 0.031) and NACV (P = 0.036). The nuclear area (P = 0.009), perimeter (P = 0.0001), circularity (P = 0.045), and larger to shorter diameter ratio (LS ratio) (P =0.02) were significantly different in the levels of the nodes involved. There was good a correlation between manual and computer-based analyses (Spearman's rho, 0.616-0.824) in nuclear size parameters and the circular rate had a negative correlation (-0.118, P = 0.664). Nuclear circularity was better assessed by computer-based analysis.

CONCLUSION

Preoperative morphometric assessment of the nuclear features may detect early cellular changes and thus, are useful in predicting nodal metastases in OSCC.

Comparative evaluation of two polymerase chain reactions targeting different genomic regions to detect Mycobacterium tuberculosis in sputum

PURPOSE

Tuberculosis remains an important health problem all over the world, especially in resource poor settings like India. The Ziehl-Neelsen (ZN) staining of sputum smear is still the method of choice in the diagnosis of tuberculosis in spite of its low sensitivity and specificity. This paper evaluates comparison of two different polymerase chain reaction (PCR) assays with sputum smear findings to detect Mycobacterium tuberculosis.

MATERIALS AND METHODS

A total of 191 sputum samples were collected from 84 patients attending a tertiary care hospital, who were suspected of having pulmonary tuberculosis, were examined by PCR targeting two different genomic regions, namely, TRC 4 by non-nested format and IS6110 insertion element by nested format in comparison to ZN staining of sputum smears.

RESULTS

Among the patients tested, 20.24% (Mid-p 95%CI: 31.5-52.4) were smear positive, 7.14% (Mid-p 95%CI: 2.94-14.26) were positive by TRC 4 PCR and 41.67% (Mid-p 95%CI: 12.7-29.8) were positive by IS6110 nested PCR (nPCR). The median age of overall positive cases was 42 years. Among the nPCR positives, the median for age of rural and peri-urban community was 46 and 32 years, respectively. The kappa coefficient between smear findings and TRC4 PCR findings was 0.27 and an agreement of 0.83 was observed (Z = 2.99; one-tailed P = 0.001). TRC 4 PCR picked two unique positives that were negative by smear and IS6110 nPCR.

CONCLUSION

The non-nested TRC 4 PCR showed inability for accurate detection of M. tuberculosis in sputum samples. The study concluded that the nPCR targeting IS6110 is superior and more sensitive than TRC 4 PCR.

1,1'-[4-(2,4-Dichloro-phen-yl)-2,6-di-methyl-1,4-di-hydro-pyridine-3,5-di-yl]diethanone

In the title compound, C(17)H(17)Cl(2)NO(2), the central 1,4-dihydro-pyridine ring adopts a flattened-boat conformation. The ethanone substituents of the dihydro-pyridine ring at positions 3 and 5 have synperiplanar (cis) or anti-periplanar (trans) conformations with respect to the adjacent C=C bonds in the dihydro-pyridine ring. The 2,4-dichloro-phenyl ring is almost planar [r.m.s. deviation = 0.0045 (1) Å] and almost perpendicular [89.27 (3)°] to the mean plane of the dihydro-pyridine ring. In the crystal, an N-H⋯O hydrogen bond links mol-ecules into a zigzag chain along the ac diagonal. C-H⋯Cl contacts form centrosymmetric dimers and additional weak C-H⋯O contacts further consolidate the packing.

Spectral Analysis and Crystal Structures of 4-(4-Methylphenyl)-6-Phenyl-2,3,3a, 4-Tetrahydro-1H-Pyrido[3,2,1-jk]Carbazole and 4-(4-Methoxyphenyl)-6-Phenyl-2,3,3a, 4-Tetrahydro-1H-Pyrido[3,2,1-jk]Carbazole

The crystal structures of 4-(4-methylphenyl)-6-phenyl-2,3,3a,4-tetrahydro-1H-pyrido[3,2,1-jk]carbazole (IIa) and 4-(4-methoxyphenyl)-6-phenyl-2,3,3a,4-tetrahydro-1H-pyrido[3,2,1-jk]carbazole (IIb) were elucidated by single crystal X-ray diffraction. Compound (IIa), C₂₈H₂₅N, crystallizes in the triclinic system, space group P-1, with a = 8.936(2) Å, b = 10.490(1) Å, c = 11.801(1) Å, α = 102.69(5)^°,  β = 103.27(3)^°, γ = 93.80(1)^°, and Z = 2. The compound (IIb), C₂₈H₂₅NO, crystallizes in the monoclinic system, space group P2₁/a, with a = 11.376(5) Å, b = 14.139(3) Å, c = 13.237(4) Å, β = 97.41(3)^°, and Z = 4. In both the structures, the pyrido ring adopts a twist boat conformation and the carbazole molecule has the twisted envelope structure with C3 and C13 at the flap. No classical hydrogen bonds are observed in the crystal structures. Details of the preparation, structures, and spectroscopic properties of the new compounds are discussed.

Synthesis, growth, crystal structure and characterization of a new organic material: glycine glutaric acid

Glycine glutaric acid, a new organic compound has been synthesized and good quality single crystals were grown by slow evaporation technique. The structure of the grown crystal was elucidated by using single crystal XRD. The presence of the functional groups was confirmed by using FT-IR spectroscopy. The optical transparency was studied by using UV-vis spectrophotometer and it was found that the crystal is having high optical transparency. The thermal stability of the crystal was studied by using thermo-gravimetric and differential thermal analyses and found that it is stable up to 150°C. The room temperature dielectric studies were also carried out over the wide frequency range: 10 mHz to 10 MHz.

rac-2-Hydroxy-2-(2-oxocyclopentyl)-1H-indene-1,3(2H)-dione

In the title compound, C₁₄H₁₂O₄, the indene unit is essentially planar [r.m.s. deviation = 0.0309 (1) Å] and the cyclo­penta­none ring adopts a twist form. In the crystal, mol­ecules are joined via pairs of O—H⋯O hydrogen bonds into centrosymmetric dimers.

Perinatal and early surgical outcome for the fetus with hypoplastic left heart syndrome: a 5-year single institutional experience

OBJECTIVES

To review our experience with the prenatal diagnosis of hypoplastic left heart syndrome (HLHS). Our goal was to establish the benchmark for perinatal and early surgical outcome in the current era, from a center with an aggressive surgical approach and a cohort with a high level of intention-to-treat.

METHODS

Outcome was assessed in fetuses with HLHS following stratification into high-risk and standard-risk categories. High risk was defined as the presence of any of the following: extracardiac, genetic or chromosomal anomalies; prematurity of < 34 weeks' gestation; additional cardiac findings such as intact or highly restrictive atrial septum, severe degree of tricuspid regurgitation or severe ventricular dysfunction. Standard risk was defined as absence of these risk factors.

RESULTS

Of 240 fetuses evaluated over 5 years, 162 (67.5%) were in the standard-risk group and 78 (32.5%) were in the high-risk group. Of the 240 sets of parents, 38 (15.8%) chose termination or non-intervention at birth at initial prenatal counseling and 185 of the neonates (77.1%) underwent first-stage Norwood surgery with 155 surviving and 30 deaths, giving an overall Norwood operative survival of 83.8%. Breakdown by risk class reveals a significant Norwood operative survival advantage for the standard-risk group (92.8%) over the high-risk group (56.5%) (P < 0.001).

CONCLUSIONS

Following prenatal diagnosis of HLHS, families should be strongly encouraged to undertake comprehensive prenatal evaluation in order to obtain an accurate prognosis. One-third have additional risk factors that limit survival outcome, however two-thirds do not and have an excellent chance of early survival.