Enantioselective synthesis of α-(3-pyrrolyl)methanamines with an aza-tetrasubstituted center under metal-free conditions.

Construction of a chiral methanamine unit at the C3 position of pyrrole is highly desirable; nevertheless, it remains challenging due to its intrinsic electronic properties. Herein, we present an operationally straightforward and direct asymmetric approach for accessing α-(3-pyrrolyl)methanamines under benign organocatalytic conditions for the first time. The one-pot transformation proceeds smoothly through an amine-catalyzed direct Mannich reaction of succinaldehyde with various -cyclic imines, followed by a Paal-Knorr cyclization with a primary amine.

Organocatalytic Asymmetric Construction of 2,6-Diazabicyclo-[2.2.2]octanes by Harnessing the Potential of an 3-Oxindolium Ion Intermediate.

Due to its structural complexity and intrinsic sensitivity of bridged aminal junction, 2,6-diazabicyclo[2.2.2]octane (2,6-DABCO) has remained a highly desirable target in synthetic chemistry.

Association between the Worst Pattern of Tumor Invasion and Epithelial-mesenchymal Transition and their Prognostic Impact on Early-stage Oral Tongue Squamous Cell Carcinoma.

Purpose: We aimed to determine the association between the worst pattern of tumor invasion (WPOI) and epithelial-mesenchymal transition (EMT) in early-stage oral tongue squamous cell carcinoma (OTSCC) with no adverse features and their impact on 2-year disease-free survival (DFS) and overall survival (OS) rates.

Methods: This prospective observational study included treatment-naive 50 patients who underwent primary surgery for OTSCC (pT1T2N0M0; AJCC 8th edition, with no adverse features) from June 1, 2020, to March 31, 2021 (minimum follow-up period, 2 years). WPOI (low- or high-invasive) and EMT (E-cadherin, N-cadherin, and vimentin expression at the tumor invasive front) were assessed.

Factors associated with delay in diagnosis of oral cancers.

Background: Oral cancer is one of the ten most common malignancies in the world and approximately 90 % of cases are OSCC. Despite the progress in available treatment modalities, the mortality of patients with OSCC has remained steadily high during the last 20 years. Survival data is strongly influenced by the timing of diagnosis: with more than 50 % of patients being diagnosed at an advanced stage, and their 5-year survival rate being less than 50 %.

Identification of antiviral phytochemicals from cranberry as potential inhibitors of SARS-CoV-2 main protease (M).

Cranberry phytochemicals are known to possess antiviral activities. In the current study, we explored the therapeutic potential of cranberry against SARS-CoV-2 by targeting its main protease (M) enzyme. Firstly, phytochemicals of cranberry origin were identified from three independent databases.

Spectrum of malignant scalp tumours and its impact on management-a tertiary care cancer centre experience.

Background: Tumours on the scalp are diverse and often exhibit site- and histology-specific characteristics. Reconstructing the scalp after oncological resection has always been challenging because of its unique anatomy.

Methodology: A retrospective review of patients with malignant scalp tumour operated on at a single institution over 10 years was performed.

Electrochemical Synthesis of 2-Aryl-3-(2-aminoaryl)quinoxalines via Oxidative Dearomatization/Ring-Opening/Cyclization Cascade Sequence of 2-Arylindoles with 1,2-Diaminoarenes.

A straightforward method has been developed to synthesize 2-aryl-3-(2-aminoaryl) quinoxalines from 2-arylindoles and 1,2-diaminoarenes under mild electrochemical conditions. The reaction proceeds through in situ generations of 2-arylindole-3-ones under electrochemical oxidative dearomatization of 2-arylindoles, followed by a ring opening-cyclization sequence with 1,2-diaminoarenes. A series of 2-aryl-3-(2-aminoaryl) quinoxalines have been prepared with moderate to good yields (up to 75%).

Impact of COVID-19 on Disease Progression and Postoperative Complications in Patients with Head and Neck Cancer.

The COVID-19 pandemic has created a remarkable challenge for the healthcare system. The delayed presentation, diagnosis, and treatment of head and neck cancer during the COVID-19 pandemic is expected to adversely affect outcomes. COVIDSurg collaborative group in 2020 concluded surgery ≥ 4 weeks after a positive COVID-19 swab result was associated with a lower risk of postoperative mortality.

Clinico pathological characteristics and survival outcome in oral cavity cancer with masticator space involvement (T4b) - A single institutional experience.

Introduction: Oral cavity cancer with the masticator space involvement is considered as very advanced localised diseas e and staged as T4b in AJCC 8th edition. NCCN guidelines consider this as inoperable. This study intends to compare the different treatment modalities in T4b oral cavity cancer and their impact on survival.

Papillary Thyroid Carcinoma Arising from Thyroglossal Cyst-an Institutional Experience over a Decade.

Papillary carcinoma constitutes 80% of thyroglossal duct cyst carcinoma (TGCC). The mainstay of treatment for TGCC is Sistrunk procedure. Due to lack of clear-cut guidelines in managing TGCC, the role of total thyroidectomy, neck dissection and adjuvant radioiodine therapy is still debatable.

Stage migration and treatment outcome in carcinoma tongue - A comparison of seventh and eighth AJCC pathological staging systems.

Background: The eighth edition of the American Joint Committee on Cancer (AJCC) for oral cancer has incorporated additional pathological features like depth of invasion (DOI) and extranodal extension (ENE) into T and N staging. The incorporation of these two factors will impact the staging and, hence, the treatment decisions. The aim of the study was to clinically validate the new staging system in predicting the outcome in patients treated for carcinoma oral tongue.

Mucosal Melanomas of the Oral Cavity: A Tertiary Care Centre Experience of Surgically Treated Cases.

Mucosal melanoma of oral cavity (MMO) is a relatively rare tumour comprising of 40% of all head and neck mucosal melanomas. This study assessed the treatment outcomes and factors affecting prognosis in oral cavity mucosal melanomas. The clinical case records of 25 cases of oral cavity mucosal melanomas treated in our institution during 2003-2013 were retrospectively reviewed.

Electrochemical Oxidative Addition of Nucleophiles on 2-Arylindoles: Synthesis of C2-Heteroquaternary Indolin-3-ones.

An electrochemical method has been developed to synthesize 2,2-disubstituted indolin-3-ones under mild conditions. A series of nucleophiles have been added to the 2-arylindole-3-ones, generated in situ under metal-free electrochemical oxidative dearomatization of 2-arylindoles, to afford 2,2-disubstituted 3-carbonyl indoles with heteroquaternary centers in 57-79% yields.

Enantioselective Direct Synthesis of C3-Hydroxyalkylated Pyrrole via an Amine-Catalyzed Aldol/Paal-Knorr Reaction Sequence.

Creating functionality with chirality at position C3 of pyrrole is challenging. An operationally simple organocatalytic method has been developed to generate functionality with a chiral tertiary/quaternary stereocenter at position C3 of pyrrole. The process proceeds through an amine-catalyzed direct aldol reaction of succinaldehyde with various acceptor carbonyls, followed by a Paal-Knorr reaction with a primary amine in the same pot.

PIFA-promoted intramolecular oxidative cyclization of pyrrolo- and indolo[1,2-]quinoxalino-appended porphyrins: an efficient synthesis of ,β-pyrrolo- and indolo[1,2-]quinoxalino-fused porphyrins.

We have developed an efficient protocol for the synthesis of ,β-pyrrolo- and indolo[1,2-]quinoxalino-fused porphyrin systems 7-9 by PIFA-promoted intramolecular oxidative cyclization of easily accessible -pyrrolo- and indolo[1,2-]quinoxalino-appended porphyrins 6a-j. The absorption spectra of ,β-pyrrolo- and indolo[1,2-]quinoxalino-fused porphyrins 7-9 displayed bathochromic shifted (100-150 nm) and broadened Soret bands and Q bands in addition to intense band near IR region. The indolo[1,2-]quinoxalino-fused porphyrin 9bZn with lower fluorescence quantum yield (0.

Catalyst-free direct regiospecific multicomponent synthesis of C3-functionalized pyrroles.

An operationally simple catalyst-free protocol for the direct regiospecific synthesis of β-(C3)-substituted pyrroles has been developed. The enamine intermediate, generated from succinaldehyde and a primary amine, was trapped with activated carbonyls before the Paal-Knorr reaction in a direct multicomponent "just-mix" fashion to furnish pyrroles with overall good yields. Several C3-substituted -alkyl/aryl/H pyrroles have been produced under open-flask conditions with high atom economy and avoiding protection-deprotection chemistry.

Two-pot synthesis and photophysical studies of 1,6-disubstituted 5-aza-indoles from succinaldehyde and -aryl propargylic-imines.

A two-pot synthesis of 5-aza-indoles has been developed from aqueous succinaldehyde and -aryl propargylic-imines. This overall protocol involves: (i) the metal-free [3 + 2] annulation of aqueous succinaldehyde and -aryl propargylic-imines to access 2-alkynyl-pyrrole-3-aldehydes and (ii) Ag-catalyzed 6--cyclization to obtain substituted 5-aza-indoles in the second pot. The 5-aza-indoles showed engaging photophysical activities, and the practicality of this pot-economic gram-scale synthesis has been demonstrated.

Asymmetric Synthesis of Bridged -Heterocycles with Tertiary Carbon Center through Barbas Dienamine-Catalysis: Scope and Applications.

A direct aza-Diels-Alder reaction between 2-aryl-3-indolin-3-ones and cyclic-enones has been developed to access chiral indolin-3-one fused polycyclic bridged compounds. This method proceeds via proline-catalyzed Barbas-dienamine intermediate formation from various cyclic-enones such as 2-cyclopenten-1-one, 2-cyclohexene-1-one, and 2-cycloheptene-1-one, followed by a reaction with 2-aryl-3-indol-3-ones. Several indolin-3-ones fusing [2.

and assays reveal potential inhibitors against 3CL main protease of SARS-CoV-2.

The COVID-19 pandemic, caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is not showing any sign of slowing down even after the ongoing efforts of vaccination. The threats of new strains are concerning, as some of them are more infectious than the original one. A therapeutic against the disease is, therefore, of urgent need.

Modeling rarefied gas-solid surface interactions for Couette flow with different wall temperatures using an unsupervised machine learning technique.

In rarefied gas flows, discontinuity phenomena such as velocity slip and temperature jump commonly appear in the gas layer adjacent to a solid boundary. Due to the physical complexity of the interactions at the gas-solid interface, particularly in the case of systems with local nonequilibrium state, boundary models with limited number of parameters cannot completely describe the reflection of gas molecules at the boundary. In this work, the Gaussian mixture (GM) model, which is an unsupervised machine learning technique, is employed to construct a statistical gas-solid surface scattering model based on the collisional data obtained from molecular dynamics (MD) simulations.

Peptide inhibitors against SARS-CoV-2 2'-O-methyltransferase involved in RNA capping: A computational approach.

The COVID-19 pandemic is still evolving and is caused by SARS-CoV-2. The 2'-O-methyltransferase (nsp16) enzyme is crucial for maintaining the stability of viral RNA for effective translation of viral proteins and its life cycle. Another protein, nsp10, is important for enzymatic activity of nsp16.

Direct catalytic synthesis of β-(C3)-substituted pyrroles: a complementary addition to the Paal-Knorr reaction.

The synthesis of β-(C3)-functionalized pyrroles is a challenging task and requires a multistep protocol. An operationally simple direct catalytic synthesis of β-substituted pyrroles has been developed. This one-pot multicomponent method combined aqueous succinaldehyde as 1,4-dicarbonyl, primary amines, and isatins to access hydroxyl-oxindole β-tethered pyrroles.

Voice Rehabilitation After Laryngectomy: A Regional Cancer Centre Experience and Review of Literature.

Alaryngeal speech in laryngectomees has revolutionized the patient outlook toward the morbid procedure and the concept of permanent stoma unlike olden era when stigma of stoma with loss of voice was rampant. To analyse acceptance of voice rehabilitation options and their success and management of complications in a tertiary care centre. All patients who underwent laryngectomy from August 2014 to 2018 June at our institution were included in the study.

Direct Amine-Catalyzed Enantioselective Synthesis of Pentacyclic Dibenzo[,][1,4]oxazepine/Thiazepine-Fused Isoquinuclidines along with DFT Calculations.

A direct protocol for the asymmetric synthesis of dibenzoxazepine/thiazepine-fused [2.2.2] isoquinuclidines is developed.