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Graphene nanoribbons (GNRs) are lengthened one-dimensional monolayer strips of graphene and have a hexagonal honeycomb lattice structure. The captivating properties like electrical conductivity, emerging band gap, optical property, thermal conductivity, high mechanical strength, and ultrahigh surface area make them a better candidate for biomedical applications. The properties can be significantly reformed and controlled by altering the edge functionalities and geometry. The exhibition of a wide potential window coupled with an ultra-high surface area to host sensing element makes GNR an excellent biosensing platform. Consequently, biosensing is one of the most explored applications of GNR. This review presents an overview of the characteristics, methods of synthesis, and biosensing applications of GNR. Overall, GNR is considered a promising platform for efficient signal transduction compared to conventional biosensing platforms. Further, it offers high electrical conductivity, large surface area, high adsorption, synergistic effects with combined materials, fast response, sensitivity, and selectivity., (Copyright © 2021 Elsevier B.V. All rights reserved.)

The present study demonstrates the development of polyphenol oxidase (PPO) biosensor for the detection of catechol using strontium copper oxide (SrCuO 2 ) and polypyrrole nanotubes (PPyNT) matrix. The SrCuO 2 micro-seeds, a perovskite compound, are synthesized by co-precipitation under pH 8.0. The as-synthesized micro-seeds are characterized by scanning electron microscopy (SEM), field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction spectroscopy (XRD). The proposed sensor is fabricated on pencil graphite (P-Gr) by successive deposition of PPyNT, SrCuO 2 , and PPO enzyme. The developed PPO/SrCuO 2 /PPyNT/P-Gr sensor is characterized by cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS) techniques. The PPO/SrCuO 2 /PPyNT/P-Gr displayed excellent electrocatalytic activity towards the oxidation and detection of catechol. The as-developed sensor showed sensitive response ascribing to limit of detection (LOD) of 0.15 μM and sensitivity of 15.60 μA μM -1  cm -2 . The fabricated sensor exhibited excellent repeatability and longer shelf life. The proposed biosensor finds its application within the broad linear range of 1-50 μM. Real sample analysis of mineral water, tap water, and domestic wastewater using developed sensor showed acceptable recovery. Hence, the biosensor endeavors its application in environmental monitoring and protection.

This work depicts the novel chromogenic system for the assay of glucose in blood samples connected with the chelate formation of sulfosalicylic acid (SSA) with iron (Fe(III)) using glucose oxidase (GOD) presented. The purple-colored Fe-SSA chelate compound formed, maintain a strong absorption at 500 nm in the acidic buffer of pH 3.8. The Beer's law limit for the assay of glucose by rate, and a one-time method is in the range of 46-1295 μmol/L and 9-1110 μmol/L sequentially. Inter and Intraday precision fluctuated amid 0.98-1.4% (n = 10), and 1.33-2.89% (n = 15) sequentially. The recovery of glucose varied from 96.6 to 102%, registering trifling interference by common interferants in blood samples. The accuracy of the outcome, LOD, and LOQ of glucose were within 90-102%, 2.376, and 7.923 μmol/L individually. The introduced method has a coefficient of correlation 0.999 with the standard kit system, and easy to ascertain serum glucose with excellent recovery and insignificant interruption. Nevertheless, the system can be recognized for selection by the biochemical laboratories., (Copyright © 2019 Elsevier Inc. All rights reserved.)

There is limited evidence to suggest that anterior approaches for the resection of ventral intramedullary lesions of the cervical spinal cord may result in superior neurological outcomes compared with those following more traditional posterior approaches. To the authors' knowledge, no report of an anterior approach to resect a ventral intramedullary capillary hemangioma exists in the literature. In the following paper, the case of a 75-year-old male who presented with progressive neck and left shoulder pain, weakness of the left hand, myelopathy, and gait imbalance is reported. Postcontrast T1-weighted MRI demonstrated a homogeneously enhancing intramedullary lesion with associated severe impingement of the cervical spinal cord at C-4. Following a C-4 corpectomy, intradural exposure revealed a vascular lesion that circumferentially enveloped the anterior spinal artery. Gross-total resection of the lesion was performed, followed by reconstruction of the corpectomy defect, without neurological deterioration. Pathology was consistent with capillary hemangioma. In this instance, the anterior approach helped to avoid unnecessary neural manipulation and allowed for early identification of normal proximal and distal segments of the anterior spinal artery, which facilitated safe dissection and gross-total removal.

Introduction: Children and adolescents with disabilities appear to have poorer oral health than their non-disabled counterparts. Individuals with disabilities or illnesses receive less oral care than the normal population., Objective: To determine the dentition status, treatment needs and risk predictors for dental caries of the institutionalized disabled individuals., Materials and Methods: A descriptive cross-sectional study was conducted with pre-tested questionnaire among 330 institutionalised disabled individuals in the age range from 3 to 22 years. The Dentition status and treatment needs were assessed by using WHO Oral health Proforma 1997. ANOVA test, chi-square test and backward conditional logistic regression analysis were performed., Results: The mean DMFT for all the groups was 1.26 and the mean deft was 0.59. Backward conditional logistic regression revealed that only age categories and disability types were significantly associated with dental caries. Individuals who were mentally retarded (OR=1.36) and in the age group of 13-17 y (OR=1.91) were more likely to develop dental caries., Conclusion: The findings of the present study showed that overall caries experience was low but the treatment need was high among these institutionalized disabled individuals.

The CuX (X = I, Br, Cl, CN)-mediated cyclization-halogenation and cyclization-cyanation reactions of beta-hydroxyalkynes and o-alkynylphenol and -aniline derivatives give rise to 3-halo- and 3-cyanofuro[3,2-b]pyrroles, 3-iodo-, 3-bromo-, and 3-cyanobenzofurans, and 3-cyanoindoles, respectively.

Furo[3,2-b]pyrroles and furo[3,2-b]pyridines can be conveniently prepared in good yields from the cycloisomerization reactions of cis-4-hydroxy-5-alkynylpyrrolidinones and cis-5-hydroxy-6-alkynylpiperidinones, respectively, using Ag(I), Pd(II)/Cu(I), or Au(I) catalysis. In one case, the cycloisomerization product was unstable and produced a furan derivative by a ring-opening reaction.

Herein, we report transition metal-catalyzed intramolecular cyclization of o-(1-alkynyl)benzenesulfonamides to afford 3-substituted benzothiazines regioselectively via a C-N bond forming reaction and Cu-catalyzed sequential C-N and C-C bond formation leading to the corresponding 3,4-disubstituted derivatives.

A new Pd-catalyzed one-pot multicomponent coupling reaction for the construction of benzene ring fused with carbocycle or heterocycle under a Cu-free condition is described.

[reaction: see text] We herein report a new synthesis of 2-(hetero)aryl-substituted pyridines via heteroarylation of arenes/heteroarenes through AlCl(3)-induced C-C bond-forming reactions. 2-Halopyridines bearing an electron-withdrawing group were reacted with a number of (hetero)arenes to give 2-aryl/heteroaryl-substituted pyridines in good yields.

Object: Familiarity with the microsurgical anatomy of the far-lateral compartment is essential for operating in patients with far-lateral discs. In this report the authors address the microsurgical anatomy studied in 24 extraforaminal lumbar disc spaces in three cadavers., Methods: Cadaveric dissections confirmed the authors' operative experience in which they found an arterial arcade to be associated with the nerve trunk. The main trunk of the lumbar artery was located lateral to the exiting nerve root in the region of intervertebral foramen. The trunk of the lumbar spinal nerve descending from the level above was 7 mm (+/- 3 mm [standard deviation]) lateral to the lumbar artery., Conclusions: Clarification of the microsurgical anatomy of the far-lateral compartment confirmed the authors' clinical impression that the optimum approach to far-lateral discs is via the inferomedial quadrant of the extraforaminal compartment. In this quadrant, exposure of the main nerve root can be facilitated by dividing the posterior primary ramus and a newly described arterial arcade that envelops the nerve trunk. Once this arcade is divided, the nerve can be retracted with relative ease and safety, and the disc can be removed more easily.

Background and Importance: Lymphoma deposits in the spine are typically extradural. However, we report the case of a 38-year-old man who had a peripheral T-cell lymphoma with both intra- and extradural involvement., Clinical Presentation: The patient presented with a 3-month history of right hip and thigh pain. Computed tomography and magnetic resonance imaging revealed features indistinguishable from those of a benign neurofibroma, except for a small area of T2-weighted signal abnormality in the third lumbar vertebral body., Intervention: A solitary lesion of the right third lumbar root with normal surrounding bone and soft tissue was excised at surgery. At immunohistopathological evaluation, a diagnosis was made of peripheral lymphoma. Postoperative evaluation did not reveal lymphoma in the cerebrospinal fluid, abdomen, chest, blood, or bone marrow. This case illustrates that lymphomas can grow in patterns indistinguishable from a tumor of a nerve root. Therefore, other treatment modalities would have been considered had the diagnosis of lymphoma been made preoperatively., Conclusion: Involvement of a solitary nerve root by lymphoma, although rare, should be suspected in all cases of nerve root neurofibroma, and magnetic resonance imaging should be performed. Even minor signal abnormalities in adjoining vertebrae signal the possibility of malignancy. Percutaneous biopsy of suspicious bony lesions and systemic evaluation can demonstrate other sites of involvement, enabling the confirmation of the diagnosis and appropriate treatment without recourse to surgery.

Neurological deterioration is commonly seen after surgical excision of clival meningiomas; however, an understanding of the risk factors associated with postoperative deterioration can lead to improvements in outcome. In 75 patients with clival meningiomas operated on over a 7-year period, the following data were studied; preoperative variables such as presenting Karnofsky scale score, age, sex, and prior operations or radiation therapy. Radiological findings on magnetic resonance imaging or arteriography, such as the development of the arachnoidal cleavage plane between tumor and the brain stem, brainstem edema, tumor size, extent of compression on the brain stem, vascular encasement, and blood supply from the basilar artery were among other data studied. In addition, intraoperative findings such as development of the arachnoid plane, vascular encasement, and the difficulty of dissection were noted. Finally, each patient's neurological and functional statuses were recorded at 1 week postoperatively and at follow-up examinations. Early postoperative functional deterioration occurred in 45 patients (60%) and ranged from mild (30 patients) to severe (three patients). Significant improvement had occurred by the time of follow-up examination in all but four patients; however, permanent postoperative dysfunction was present in 12 patients. Statistical analysis revealed significant correlations between early functional deterioration and preoperative Karnofsky scale scores, male gender, radiological findings of the absence of an arachnoid plane, edema of the brain stem, and arteriographic supply from the basilar artery. Operative features included difficulty with dissection, an absent arachnoidal cleavage plane, and incomplete tumor resection. Permanent functional deterioration was statistically associated with the following: blood supply from the basilar artery, difficulty of dissection, incomplete tumor resection, and early postoperative dysfunction. Logistical regression analysis revealed that the most important risk factor for early postoperative deterioration was tumor size. Patients with large or giant tumors had a 6.7 to 13 times greater risk of functional deterioration, respectively, than patients with small- or medium-sized tumors. Excluding tumor size, the most important factor for permanent deterioration was blood supply from the basilar artery. Patients in this category had a 4.4 times greater risk of permanent functional deterioration. Three stages of tumor relationship to the brainstem arachnoid and pial membranes are proposed. Based on the results of this clinical study of clival meningiomas, suggestions are made for changes in the management strategy of these difficult lesions.

A case of giant saccular aneurysm in early childhood is reported. An internal carotid aneurysm presenting with episodic headache was successfully clipped with complete relief of symptoms. The patient was also investigated for a possible collagen deficiency which proved negative. Clinical features and pathogenesis of this rare lesion are discussed.