Identification, crystallization, and first X-ray structure analyses of phenyl boronic acid-based inhibitors of human carbonic anhydrase-II.

Human carbonic anhydrases (hCAs) play a central role in various physiological processes in the human body. HCAs catalyze the reversible hydration of CO2 into HCO3-, and hence maintains the fluid and pH balance. Overexpression of CA II is associated with diseases, such as glaucoma, and epilepsy. Therefore, CAs are important clinical targets and inhibition of different isoforms, especially hCA II is used in treatment of glaucoma, altitude sickness, and epilepsy. Therapeutically used CA inhibitors (CAI) are sulfonamide-based, such as acetazolamide, dichlorphenamide, methazolamide, ethoxzolamide, etc. However, they exhibit several undesirable effects such as numbness, tingling of extremities, malaise, metallic taste, fatigue, renal calculi, and metabolic acidosis. Therefore, there is an urgent need to identify safe and effective inhibitors of the hCAs. In this study, different phenyl boronic acids 1-5 were evaluated against bovine (bCA II) and hCA II. Among all, compound 1 (4-acetylphenyl boronic acid) was found to be active against bCAII and hCA II with IC50 values of 246 ± 0.48 and 281.40 ± 2.8 µM, respectively, while the remaining compounds were found in-active. Compound 1 was identified as competitive inhibitor of hCA II enzyme (Ki = 283.7 ± 0.002 µM). Additionally, compound 1 was found to be non-toxic against BJ Human fibroblast cell line. The X-ray crystal structure for hCA II in-complex with compound 1 was evaluated to a resolution of 2.6 Å. In fact, this the first structural analysis of a phenyl boron-based inhibitor bound to hCA II, allowing an additional structure-activity analysis of the compounds. Compound 1 was found to be directly bound in the active site of hCA II by interacting with His94, His119, and Thr199 residues. In addition, a bond of 3.11 Å between the zinc ion and coordinated boron atom of the boronic acid moiety of compound 1 was also observed, contributing to binding affinity of compound 1 for hCA II. PDB ID: 8IGF.

Surface-enhanced Raman spectroscopy for characterization of filtrates of blood serum samples from patients with tuberculosis obtained by 50 kDa filtration devices.

The ability of surface-enhanced Raman spectroscopy (SERS) to generate spectroscopic fingerprints has made it an emerging tool for biomedical applications. The objective of this study is to confirm the potential use of Raman spectroscopy for early disease diagnosis based on blood serum. In this study, a total of sixty blood serum samples, consisting of forty from diseased patients and twenty (controls) from healthy individuals, was used. Because disease biomarkers, found in the lower molecular weight fraction, are suppressed by higher molecular weight proteins, 50 kDa Amicon ultrafiltration centrifugation devices were used to produce two fractions from whole blood serum consisting of a filtrate, which is a low molecular weight fraction, and a residue, which is a high molecular weight fraction. These fractions were then analyzed, and their SERS spectral data were compared with those of healthy fractions. The SERS technique was utilized on blood serum, filtrate and residue of patients with tuberculosis to identify characteristic SERS spectral features associated with the development of disease, which can be used to differentiate them from healthy samples using silver nanoparticles as a SERS substrate. For further analysis, the effective chemometric technique of principal component analysis (PCA) was used to qualitatively differentiate all the analyzed samples based on their SERS spectral features. Partial least squares discriminant analysis (PLS-DA) accurately classified the filtrate portions of healthy and tuberculosis samples with 97% accuracy, 97% specificity, 98% sensitivity, and an area under the receiver operating characteristic (AUROC) curve of 0.74.

Source tracking of extensively drug resistant Salmonella Typhi in food and raw vegetables using molecular approaches.

INTRODUCTION: Extensively drug resistant (XDR) strains of the Salmonella lineages have been reported to spread from Africa to South Asia. XDR strains are resistant to fluoroquinolones, chloramphenicol, co-trimoxazole, and ampicillin, resulting in treatment failure. The objectives of this study included the investigation of transmission of S. Typhi lineages and the identification of the potentially contaminated sources of the XDR typhoid outbreak from different urban areas by using molecular techniques. METHODOLOGY: Environmental samples, including food samples, were collected from different towns and the susceptibility of each isolate to the antimicrobial agents was examined. Molecular identification of different Salmonella lineages including S. Typhi, S. Paratyphi A, H58, and XDR was carried out through multiplex PCR. RESULTS AND CONCLUSIONS: A total of 328 environmental samples including raw vegetables, water, and bakery items were collected. More than half of the tested samples (64%) found harboring Salmonella spp. The Salmonella was confirmed through PCR amplification of species-specific markers that showed the presence of S. Typhi (40%), S. Paratyphi A (8%), H58 (7%), and XDR S. Typhi (6%). Raw vegetables had the highest number of Salmonella spp., indicating consumption of raw vegetables as a possible source of salmonellosis. XDR status was also affirmed through phenotypic antimicrobial susceptibility testing.

Pediatric craniopharyngioma: a 20-year study on epidemiological features, clinical presentation, and survival outcomes in a tertiary care center from LMIC.

INTRODUCTION: Craniopharyngioma constitutes approximately 10% of primary brain tumors in children. It can cause considerable morbidity and mortality due to the local aggressiveness of the tumor itself or its management affecting the hypothalamus-pituitary axis and optic pathway involvement. There is very scarce data available from LMIC which makes the management controversial where multidisciplinary teams are already not available in most of the centers. This is a single-center cross-sectional retrospective review of 20-year record of 49 patients with craniopharyngioma treated between 2001 and 2020 at Aga Khan University Hospital, a tertiary care center in Karachi, Pakistan. METHODS: We have assessed the epidemiological data of children presenting with the diagnosis of craniopharyngioma, treatment modalities used, and neurological, endocrine, and hypothalamic complications in these patients. The assessment involved a retrospective review of medical records and medical follow-up. RESULTS: Out of a total of 49 patients, 26 (53%) were male, and 23 (46.9%) were female. The mean age was 9.5 years (SD ± 4.5 years). Most common symptoms at initial presentation were headache 41 (83.6%), visual deficit 40 (81.6%), nausea and vomiting 26 (53%), and endocrine abnormalities 16 (32%). Treatment modalities used at our center include gross total resection 11 (22%) and subtotal resection 38 (77%) out of total, while 6 (12.2%) patients received intracystic interferon. Histopathologic findings of the majority of patients (40 (81%)) revealed an adamantinomatous type of tumor. Only 23 (46.9%) children followed in clinic post-op. Median follow-up after craniopharyngioma presentation was 5 years (± 2.1 SD, range: 2-10 years). Pituitary hormone deficiencies (98%) and visual disturbances (75%) were the most common long-term health conditions observed. CONCLUSIONS: Since pituitary hormone deficiencies and visual disturbance were the most common long-term health conditions observed in our study, these patients require a multidisciplinary team follow-up to improve their quality of life.

Synthesis, Characterization, and Evaluation of Antifungal Activity of 1-Butyl-3-hexyl-1H-imidazol-2(3H)-selenone by Surface-Enhanced Raman Spectroscopy.

In the present research work, a selenium N-heterocyclic carbene (Se-NHC) complex/adduct was synthesized and characterized by using different analytical methods including FT-IR, 1HNMR, and 13CNMR. The antifungal activity of the Se-NHC complex against Aspergillus flavus (A. flavus) fungus was investigated with disc diffusion assay. Moreover, the biochemical changes occurring in this fungus due to exposure of different concentrations of the in-house synthesized compound are characterized by surface-enhanced Raman spectroscopy (SERS) and are illustrated in the form of SERS spectral peaks. SERS analysis yields valuable information about the probable mechanisms responsible for the antifungal effects of the Se-NHC complex. As demonstrated by the SERS spectra, this Se-NHC complex caused denaturation and conformational changes in the proteins as well as decomposition of the fungal cell membrane. The SERS spectra were analyzed using two chemometric tools such as principal component analysis (PCA) and partial least-squares discriminant analysis (PLS-DA). The fungal samples' SERS spectra were differentiated using PCA, while various groups of spectra were discriminated with ultrahigh sensitivity (98%), high specificity (99.7%), accuracy (100%), and area under the receiver operating characteristic curve (87%) using PLS-DA.

Qualitative and Quantitative Analysis of Azithromycin as Solid Dosage by Raman Spectroscopy.

Active pharmaceutical ingredients (APIs) and excipients are main drug constituents that ought to be identified qualitatively and quantitatively. Raman spectroscopy is aimed to be an efficient technique for pharmaceutical analysis in solid dosage forms. This technique can successfully be used in terms of qualitative and quantitative analysis of pharmaceutical drugs, their APIs, and excipients. In the proposed research, Raman spectroscopy has been employed to quantify Azithromycin based on its distinctive Raman spectral features by using commercially prepared formulations with altered API concentrations and excipients as well. Along with Raman spectroscopy, principal component analysis and partial least squares regression (PLSR), two multivariate data analysis techniques have been used for the identification and quantification of the API. For PLSR, goodness of fit of the model (R2) was found to be 0.99, whereas root mean square error of calibration was 0.46 and root mean square error of prediction was 2.42, which represent the performance of the model. This study highlights the efficiency of Raman spectroscopy in the field of pharmaceutics by preparing pharmaceutical formulations of any drug to quantify their API and excipients to compensate for the commercially prepared concentrations.

Synthesis of novel coumarin-based thiosemicarbazones and their implications in diabetic management via in-vitro and in-silico approaches.

Diabetes mellitus has a high prevalence rate and it has been deemed a severe chronic metabolic disorder with long-term complications. This research aimed to identify compounds that could potentially inhibit the vital metabolic enzyme α-glucosidase and thereby exert an anti-hyperglycemic effect. The main goal was to establish an effective approach to control diabetes. To proceed with this study, a series of novel coumarin-derived thiosemicarbazones 3a-3m was synthesized and examined using a variety of spectroscopic methods. Moreover, all the compounds were subjected to α-glucosidase inhibition bioassay to evaluate their antidiabetic potential. Fortunately, all the compounds exhibited several folds potent α-glucosidase inhibitory activities with IC50 values ranging from 2.33 to 22.11 µM, in comparison to the standard drug acarbose (IC50 = 873.34 ± 1.67 µM). The kinetic studies of compound 3c displayed concentration-dependent inhibition. Furthermore, the binding modes of these molecules were elucidated through a molecular docking strategy which depicted that the thiosemicarbazide moiety of these molecules plays a significant role in the interaction with different residues of the α-glucosidase enzyme. However, their conformational difference is responsible for their varied inhibitory potential. The molecular dynamics simulations suggested that the top-ranked compounds (3c, 3g and 3i) have a substantial effect on the protein dynamics which alter the protein function and have stable attachment in the protein active pocket. The findings suggest that these molecules have the potential to be investigated further as novel antidiabetic medications.

Proliferative Diabetic Retinopathy Diagnosis Using Varying-Scales Filter Banks and Double-Layered Thresholding.

Diabetic retinopathy is one of the abnormalities of the retina in which a diabetic patient suffers from severe vision loss due to an affected retina. Proliferative diabetic retinopathy (PDR) is the final and most critical stage of diabetic retinopathy. Abnormal and fragile blood vessels start to grow on the surface of the retina at this stage. It causes retinal detachment, which may lead to complete blindness in severe cases. In this paper, a novel method is proposed for the detection and grading of neovascularization. The proposed system first performs pre-processing on input retinal images to enhance the vascular pattern, followed by blood vessel segmentation and optic disc localization. Then various features are tested on the candidate regions with different thresholds. In this way, positive and negative advanced diabetic retinopathy cases are separated. Optic disc coordinates are applied for the grading of neovascularization as NVD or NVE. The proposed algorithm improves the quality of automated diagnostic systems by eliminating normal blood vessels and exudates that might cause hindrances in accurate disease detection, thus resulting in more accurate detection of abnormal blood vessels. The evaluation of the proposed system has been carried out using performance parameters such as sensitivity, specificity, accuracy, and positive predictive value (PPV) on a publicly available standard retinal image database and one of the locally available databases. The proposed algorithm gives an accuracy of 98.5% and PPV of 99.8% on MESSIDOR and an accuracy of 96.5% and PPV of 100% on the local database.

Molecular and genetic perspectives of cold tolerance in wheat.

Environmental variation is the most crucial problem as it is causing food insecurity and negatively impacts food availability, utilization, assessment, and stability. Wheat is the largest and extensively cultivated staple food crop for fulfilling global food requirements. Abiotic stresses including salinity, heavy metal toxicity, drought, extreme temperatures, and oxidative stresses being the primary cause of productivity loss are a serious threat to agronomy. Cold stress is a foremost ecological constraint that is extremely influencing plant development, and yield. It is extremely hampering the propagative development of plant life. The structure and function of plant cells depend on the cell's immune system. The stresses due to cold, affect fluid in the plasma membrane and change it into crystals or a solid gel phase. Plants being sessile in nature have evolved progressive systems that permit them to acclimatize the cold stress at the physiological as well as molecular levels. The phenomenon of acclimatisation of plants to cold stress has been investigated for the last 10 years. Studying cold tolerance is critical for extending the adaptability zones of perennial grasses. In the present review, we have elaborated the current improvement of cold tolerance in plants from molecular and physiological viewpoints, such as hormones, the role of the posttranscriptional gene, micro RNAs, ICE-CBF-COR signaling route in cold acclimatization and how they are stimulating the expression of underlying genes encoding osmoregulatory elements and strategies to improve cold tolerance in wheat.

Perceptions Of Medical Students About Research At Undergraduate Level.

BACKGROUND: Undergraduate (UG) research is new but important concept in modern science. It is considered as an effective educational tool for enhancing the undergraduate medical experience. The objectives of the study were to know the perceptions of UG medical students towards research, main motivating factors and barriers faced by the students. METHODS: It was Crosssectional study with both quantitative and qualitative portions conducted in Ayub Medical College (AMC) from November 2018 to April 2019. The quantitative portion of the study was based on a simple questionnaire with 9 closed ended questions completed by 215 participants selected using stratified random sampling technique. Data was analysed using SPSS 20.0. The Qualitative portion of the study was based on 8 Focused Group Discussions (FGDs), two from each year, with 6-10 participants. The interviews were recorded and reported by obtaining informed consent from each participant. The audio recording of the FGDs was transcribed verbatim and content analysis was done by conventional content analysis. RESULTS: Out of 215, 128 (59.5%) had a previous research experience mostly as a compulsory requirement of undergraduate curriculum; 134 (62.3%) were aware that research is a part of their curriculum. Lack of resources and lack of interest of students was main barrier, i.e., 152 (70.7%). For 133 (61.8%) participants, the main motivating factor was learning research methodology. CONCLUSIONS: Students were aware about research and their awareness about research increased with increasing year in medical school. Hardly any student had a research experience beforehand they took part in mandatory research in 4th year.

The Effect of a Diverse Dataset for Transfer Learning in Thermal Person Detection.

Thermal cameras are popular in detection for their precision in surveillance in the dark and for privacy preservation. In the era of data driven problem solving approaches, manually finding and annotating a large amount of data is inefficient in terms of cost and effort. With the introduction of transfer learning, rather than having large datasets, a dataset covering all characteristics and aspects of the target place is more important. In this work, we studied a large thermal dataset recorded for 20 weeks and identified nine phenomena in it. Moreover, we investigated the impact of each phenomenon for model adaptation in transfer learning. Each phenomenon was investigated separately and in combination. the performance was analyzed by computing the F1 score, precision, recall, true negative rate, and false negative rate. Furthermore, to underline our investigation, the trained model with our dataset was further tested on publicly available datasets, and encouraging results were obtained. Finally, our dataset was also made publicly available.

Heterogeneous ion exchange membranes based on thermoplastic polyurethane (TPU): effect of PSS/DVB resin on morphology and electrodialysis.

In this research, novel heterogeneous cation exchange membranes based on thermoplastic polyurethane (TPU) have been prepared by the solution casting technique. The effects of incorporation level of sulfonated polystyrene divinyl-benzene (PSS/DVB) resin on water uptake, ion exchange capacity, membrane potential and salt extraction have been elucidated. Morphological and water uptake studies suggested a two-phase heterogeneous membrane morphology owing to the presence of hard and soft segments in the TPU backbone and swelling of PSS/DVB particles. This morphology was shifted to a semi-gelled morphology throughout the membrane bulk when resin loading exceeded 50 wt%. The physically cross-linked hard segments in the TPU backbone ensured a compact membrane morphology and prevented the formation of water channels. The membrane potential showed that increasing the resin content increased the membrane transport number (max. 0.95) up to 50 wt% resin loading and beyond this, the transport number started decreasing showing a pronounced effect of voids and water flow channels developing on excessive swelling. The permselectivity reached a maximum (up to 0.92) and salt extraction values also increased (by varying voltage) up to 50 wt% loading and started decreasing beyond this optimum content. This study shows successful development of low-cost heterogeneous cation exchange membranes based on TPU with acceptable electrochemical properties.

Evaluation of the efficacy of different sources of omega-3 fatty acids in polycystic ovarian syndrome (PCOS) induced rats.

The study was planned to check the beneficial effects of various sources of omega-3 fatty acids (synthetic, flaxseed oil, fish oil) on 45 Wistar female rats. The rats were divided into five groups and assigned to different diets i.e. NC (Negative control), PC (Positive control), SO (Synthetic omega-3 250mg/kg/orally/daily), FO (flaxseed oil 250mg/kg/orally/daily) and F (fish oil 250mg/kg/orally/diet). Animals fed on different diets were induced PCOS by an intramuscular (IM) injection of estradiol-valerate (4mg/rat/IM) except NC group. Results of the lipid profile indicated that F showed highest increase in HDL level (35.67±1.45), while cholesterol, LDL, triglycerides, blood glucose and body weight were reduced in all three treatment groups. In case of a hormonal profile, testosterone, luteinizing hormone (LH) and insulin levels showed a significant reduction after treatments. It can be concluded form the study that different sources of omega-3 fatty acids can be a new approach to treat the symptoms of PCOS.

High-Performance Flexible Ultraviolet Photodetectors with Ni/Cu-Codoped ZnO Nanorods Grown on PET Substrates.

As a developing technology for flexible electronic device fabrication, ultra-violet (UV) photodetectors (PDs) based on a ZnO nanostructure are an effective approach for large-area integration of sensors on nonconventional substrates, such as plastic or paper. However, photoconductive ZnO nanorods grown on flexible substrates have slow responses or recovery as well as low spectral responsivity R because of the native defects and inferior crystallinity of hydrothermally grown ZnO nanorods at low temperatures. In this study, ZnO nanorod crystallites are doped with Cu or Ni/Cu when grown on polyethylene terephthalate (PET) substrates in an attempt to improve the performance of flexible PDs. The doping with Ni/Cu or Cu not only improves the crystalline quality but also significantly suppresses the density of deep-level emission defects in as-grown ZnO nanorods, as demonstrated by X-ray diffraction and photoluminescence. Furthermore, the X-ray photoelectron spectroscopy analysis shows that doping with the transition metals significantly increases the oxygen bonding with metal ions with enhanced O/Zn stoichiometry in as-grown nanorods. The fabricated flexible PD devices based on an interdigitated electrode structure demonstrates a very high R of ~123 A/W, a high on-off current ratio of ~130, and a significant improvement in transient response speed exhibiting rise and fall time of ~8 and ~3 s, respectively, by using the ZnO nanorods codoped by Ni/Cu.

Effects of inosine 5'-monophosphate supplementation in high fishmeal and high soybean diets on growth, immune-related gene expression in gibel carp (Carassius auratus gibelio var. CAS â ¢), and its challenge against Aeromonas hydrophila infection.

The present study was conducted to evaluate dietary inosine 5'-monophosphate (5'-IMP) on growth, immune genes expression and disease resistance against Aeromonas hydrophila in juvenile gibel carp (Carassius auratus gibelio var. CAS Ⅲ) (initial body weight: 7.48 g). Six diets were formulated containing exogenous 5'-IMP at three gradient levels (0, 0.1% and 0.2%) in the high dietary fishmeal group (15% fishmeal: D1, D2, D3) and in the high dietary soybean meal group (33% soybean meal: D4, D5, D6). Each diet was randomly allotted to triplicate tanks in a recirculating system. After the feeding trial, fish were exposed to Aeromonas hydrophila challenge. Hematological and immunological responses were analyzed before and after challenge. The results indicated that feeding rate in all 5'-IMP supplemented treatments (D2, D3, D5 and D6) and daily growth coefficient in D5 and D6 were reduced compared with those of respective control treatments (D1 and D4) without 5'-IMP addition (P < 0.05). The cumulative survival rates were numerically improved by dietary 5'-IMP supplementation (P > 0.05). Compared with the respective control treatment, in the high fishmeal group, plasma SOD and MPO were significantly elevated in D3 at the end of feeding trial (P < 0.05), plasma SOD and lysozyme were significantly increased in D3 after bacterial challenge (P < 0.05); in high soybean meal group, plasma lysozyme activity was significantly elevated in D5 post bacterial challenge (P < 0.05). Most of the expression of immune related genes (intelectin, major histocompatibility complex class II ß (MHC II ß), Complement 3 (C3), Complement component C7-1 (ccC7), lysozyme C, Interleukin 1ß (IL-1ß), Tumor necrosis factor α1 (TNF-α1), Transforming growth factor-beta (TGF-ß) and Interleukin 8 (IL-8)) in spleen, kidney and liver of the fish were significantly affected by supplementation of 5'-IMP at the end of feeding trial and post bacterial challenge. Additionally, adding 5'-IMP in high soybean meal diets exerted further effects of promoting immunity than counterparts in high fishmeal diets. Considering enhanced disease resistance, the immunopotentiation of 5'-IMP was manifested when the addition level was 0.1% in high soybean meal diets and 0.2% in high fishmeal diets.

Anticancer, antimicrobial and antioxidant potential of sterically tuned bis-N-heterocyclic salts.

The current study was conducted to evaluate the antimicrobial, antioxidant, antileishmanial and cytotoxic potential of designed derivatives of 1,1'-(1,3-phenylenebis(methylene))bis(3-alkyl/aryl-1H-benzimidazol-3-ium) salts. The antibacterial potential of the test compounds was investigated against Staphylococcus aureus, Pseudomonas aeruginosa and two methicillin-resistant S. aureus (MRSA) strains (MRSA10, MRSA11), where compound 6 showed the best results. For brine shrimp lethality bioassay (BSLB), compound 6 again showed up to 100% mortality at 200 µg/mL and 56.7% mortality at 6.25 µg/mL. Antileishmanial assay was performed against Leishmania tropica at 20 µg/mL dosage, where 6 showed the most promising activity with 16.26% survival (83.74% mortality; IC50=14.63 µg/mL). The anticancer potential of the selected benzimidazole derivatives was evaluated against two selected cell lines (human colorectal cancer, HCT-116 and breast adenocarcinoma, MCF-7) using sulforhodamine B (SRB) assay. Compound 6 was found to be the most effective cytotoxic compound with 75% inhibition of HCT-116 proliferation at 1 mg/mL concentration. Succinctly, 6 exhibited impressive pharmacological potential that might be attributed to its higher lipophilic character owing to the longer N-substituted alkyl chains when compared to the other test compounds.

Induced Photonic Response of ZnO Nanorods Grown on Oxygen Plasma-Treated Seed Crystallites.

We examined the influence of O2 plasma treatment for the ZnO seed layer (SL) crystallites on the material characteristics of ZnO nanorods (NRs) synthesized by the hydrothermal method. Diode photocurrent and photo-response transient characteristics of the p-Si/n-ZnO-NR heterojunction-based ultraviolet (UV) photodetectors were also examined according to the plasma treatment for the SLs. The superior optical properties of NRs were measured from the photoluminescence by exhibiting 4.6 times greater near-band edge emission when grown on the O2-plasma-treated SL. The degree of (002) orientation of the NR crystals was improved from 0.67 to 0.95, as revealed by X-ray diffraction analysis, and a higher NR surface density of ~80 rods/µm² with a smaller mean diameter of 65 nm were also observed by the SL modification using plasma-treatment. It was shown by X-ray photo-electron spectroscopy that this improvement of NR crystalline quality was due to the recovery of stoichiometric oxygen with significant reduction of oxygenated impurities in the SL crystals and the subsequent low-energy growth mode for the NRs. UV PDs fabricated by the proposed SL plasma treatment technique showed significantly enhanced UV-to-dark current ratio from 2.0 to 83.7 at a forward bias of +5 V and faster photo-response characteristics showing the reduction in recovery time from 16 s to 9 s.

Evolution of Structural and Optical Properties of ZnO Nanorods Grown on Vacuum Annealed Seed Crystallites.

In this study, the ambient condition for the as-coated seed layer (SL) annealing at 350 °C is varied from air or nitrogen to vacuum to examine the evolution of structural and optical properties of ZnO nanorods (NRs). The NR crystals of high surface density (~240 rods/µm²) and aspect ratio (~20.3) show greatly enhanced (002) degree of orientation and crystalline quality, when grown on the SLs annealed in vacuum, compared to those annealed in air or nitrogen ambient. This is due to the vacuum-annealed SL crystals of a highly preferred orientation toward (002) and large grain sizes. X-ray photoelectron spectroscopy also reveals that the highest O/Zn atomic ratio of 0.89 is obtained in the case of vacuum-annealed SL crystals, which is due to the effective desorption of hydroxyl groups and other contaminants adsorbed on the surface formed during aqueous solution-based growth process. Near band edge emission (ultra violet range of 360-400 nm) of the vacuum-annealed SLs is also enhanced by 44% and 33% as compared to those annealed in air and nitrogen ambient, respectively, in photoluminescence with significant suppression of visible light emission associated with deep level transition. Due to this improvement of SL optical crystalline quality, the NR crystals grown on the vacuum-annealed SLs produce ~3 times higher ultra violet emission intensity than the other samples. In summary, it is shown that the ZnO NRs preferentially grow along the wurtzite c-axis direction, thereby producing the high crystalline quality of nanostructures when they grow on the vacuum-annealed SLs of high crystalline quality with minimized impurities and excellent preferred orientation. The ZnO nanostructures of high crystalline quality achieved in this study can be utilized for a wide range of potential device applications such as laser diodes, light-emitting diodes, piezoelectric transducers and generators, gas sensors, and ultraviolet detectors.