SecureVision: Advanced Cybersecurity Deepfake Detection with Big Data Analytics.

SecureVision is an advanced and trustworthy deepfake detection system created to tackle the growing threat of 'deepfake' movies that tamper with media, undermine public trust, and jeopardize cybersecurity. We present a novel approach that combines big data analytics with state-of-the-art deep learning algorithms to detect altered information in both audio and visual domains. One of SecureVision's primary innovations is the use of multi-modal analysis, which improves detection capabilities by concurrently analyzing many media forms and strengthening resistance against advanced deepfake techniques. The system's efficacy is further enhanced by its capacity to manage large datasets and integrate self-supervised learning, which guarantees its flexibility in the ever-changing field of digital deception. In the end, this study helps to protect digital integrity by providing a proactive, scalable, and efficient defense against the ubiquitous threat of deepfakes, thereby establishing a new benchmark for privacy and security measures in the digital era.

Deep learning model for automated diagnosis of degenerative cervical spondylosis and altered spinal cord signal on MRI.

BACKGROUND CONTEXT: A deep learning (DL) model for degenerative cervical spondylosis on MRI could enhance reporting consistency and efficiency, addressing a significant global health issue. PURPOSE: Create a DL model to detect and classify cervical cord signal abnormalities, spinal canal and neural foraminal stenosis. STUDY DESIGN/SETTING: Retrospective study conducted from January 2013 to July 2021, excluding cases with instrumentation. PATIENT SAMPLE: Overall, 504 MRI cervical spines were analyzed (504 patients, mean=58 years±13.7[SD]; 202 women) with 454 for training (90%) and 50 (10%) for internal testing. In addition, 100 MRI cervical spines were available for external testing (100 patients, mean=60 years±13.0[SD];26 women). OUTCOME MEASURES: Automated detection and classification of spinal canal stenosis, neural foraminal stenosis, and cord signal abnormality using the DL model. Recall(%), inter-rater agreement (Gwet's kappa), sensitivity, and specificity were calculated. METHODS: Utilizing axial T2-weighted gradient echo and sagittal T2-weighted images, a transformer-based DL model was trained on data labeled by an experienced musculoskeletal radiologist (12 years of experience). Internal testing involved data labeled in consensus by 2 musculoskeletal radiologists (reference standard, both with 12-years-experience), 2 subspecialist radiologists, and 2 in-training radiologists. External testing was performed. RESULTS: The DL model exhibited substantial agreement surpassing all readers in all classes for spinal canal (κ=0.78, p<.001 vs. κ range=0.57-0.70 for readers) and neural foraminal stenosis (κ=0.80, p<.001 vs. κ range=0.63-0.69 for readers) classification. The DL model's recall for cord signal abnormality (92.3%) was similar to all readers (range: 92.3-100.0%). Nearly perfect agreement was demonstrated for binary classification (grades 0/1 vs. 2/3) (κ=0.95, p<.001 for spinal canal; κ=0.90, p<.001 for neural foramina). External testing showed substantial agreement using all classes (κ=0.76, p<.001 for spinal canal; κ=0.66, p<.001 for neural foramina) and high recall for cord signal abnormality (91.9%). The DL model demonstrated high sensitivities (range:83.7%-92.4%) and specificities (range:87.8%-98.3%) on both internal and external datasets for spinal canal and neural foramina classification. CONCLUSIONS: Our DL model for degenerative cervical spondylosis on MRI showed good performance, demonstrating substantial agreement with the reference standard. This tool could assist radiologists in improving the efficiency and consistency of MRI cervical spondylosis assessments in clinical practice.

Probing Deuteration-Induced Phase Separation in Supported Lipid Monolayers using Hyperspectral TERS Imaging.

In this study, we investigate the impact of deuteration on the formation of phase-separated domains in supported lipid monolayers using hyperspectral Tip-Enhanced Raman Spectroscopy (TERS) imaging. The intricate organization of biological membranes plays a crucial role in cellular functions. Various factors that influence domain formation have been identified in previous studies such as lipid tail length and cholesterol concentration. Deuterium labeling of lipids has proven useful for probing cellular structures and dynamics, but its impact on lipid phase separation remains underexplored. By examining 1:1 mixed monolayers of dipalmitoylphosphatidylcholine (DPPC) and deuterated DPPC on Au(111) surfaces, we reveal partial segregation of domains rich in deuterated and nondeuterated lipids. This study addresses a gap in knowledge by examining the impact of deuteration on lipid tail behavior, offering new insights into how even subtle structural modifications can influence phase behavior. Furthermore, it demonstrates that TERS can be a powerful, nondestructive, and label-free nanoanalytical tool for analyzing lipid membranes and advance the field of membrane biophysics.

Five-year radiological outcomes between decompression alone and decompression with an interlaminar device for lumbar spinal stenosis.

Background: There is limited literature regarding radiological outcomes in the use of interlaminar devices as an adjunct to decompression compared to decompression alone (DA) for symptomatic lumbar spinal stenosis (LSS). This study aims to assess and compare 5-year radiological outcomes following spinal decompression and decompression with ILD (D + ILD). Methods: We conducted a retrospective review of prospectively collected data of 94 patients who underwent spinal decompression with or without ILD insertion between 2007-2015. Patients with symptomatic LSS who met the study criteria were offered spinal decompression with or without ILD insertion. Those patients who accepted ILD insertion were placed in the D + ILD group (n=39); while those opting for DA, were placed in the DA group (n=55). Radiological indices were assessed preoperatively, immediate post-operative, 2 years and 5 years postoperatively. Results: There were a total of 94 patients with 55 in the DA group and 39 in the D + ILD group. In both groups, there was no significant change post-operatively in the sagittal balance parameters namely, the mean pelvic incidence, pelvic tilt, sacral slope and pelvic incidence minus lumbar lordosis (PI - LL) during the 5-year follow-up. Comparing between the groups, there was no significant difference in sagittal balance parameters. Comparing between DA versus D + ILD, there was no significant difference in overall lordosis, but the D + ILD had a significant reduction in sagittal angle (at the index level) of 2.3° compared to the DA group (P=0.01). In the control group, there was no significant difference in the anterior disc, posterior disc and foraminal height post-operatively. In the D + ILD group, there was a significant mean increase of 1.3 mm in anterior disc height, 1.8 mm in posterior disc height and 4.7 mm in foraminal height compared to the control group. In both groups, there was significant improvement in all clinical outcomes namely 36-item short form survey physical component summary (SF36 PCS), 36-item short form survey mental component summary (SF36 MCS) and visual analogue scale (VAS). Comparing the groups, there was significant improvement in the D + ILD group in SF36 MCS (P=0.01) but no difference in SF36 PCS or VAS. Reoperation rates were equivalent. Conclusions: Our study found that in the management of lumbar stenosis, the use of an ILD as an adjunct device compared to DA had significant improvement in anterior disc, posterior disc and foraminal height with expected focal kyphosis at the level of intervention without change in the lumbar lordosis and sagittal balance at 5 years.

AB074. Propensity-score matched analysis to evaluate the safety and utility of intraoperative cell-salvaged autologous blood transfusion in metastatic spine tumour surgery.

BACKGROUND: Blood loss is an important consideration in metastatic spine tumour surgery (MSTS). Allogeneic blood transfusion (ABT) is the current standard of blood replenishment for MSTS despite known complications. Salvaged blood transfusion (SBT) through intraoperative cell salvage addresses the majority of complications related to ABT. However, the use of SBT in MSTS still remains controversial. We aim to conduct a prospective propensity-score (PS) matched analysis to evaluate the long-term clinical outcomes of intraoperative cell salvage (IOCS) in MSTS. METHODS: Our study included 98 patients who underwent MSTS from 2014-2017. A PS matched cohort was created using the relevant and available predictors of treatment assignment and outcomes of interest. Clinical outcomes consisting of overall survival (OS), as well tumour progression (TP) that was evaluated using RECIST (v1.1) were compared in the matched cohort. RESULTS: Our study had a total of 98 patients with a mean age of 60 years old. A total of 33 patients received SBT. Overall median blood loss was 600 mL [interquartile range (IQR): 300-1,000 mL] and overall median blood transfusion (BT) was 620 mL (IQR: 110-1,600 mL). Group PS matching included 30 patients who received ABT and 28 patients who received SBT. There was also no significant difference between the OS of patients who underwent ABT or SBT (P=0.19). SBT did not show any significant increase in 4-year tumour progression [PS matched hazard ratio (HR) 3.659; 95% confidence interval (CI): 0.346-38.7; P=0.28]. CONCLUSIONS: SBT has been shown to have similar clinical outcomes to that of ABT in patients undergoing MSTS, with potential benefits of avoiding complications and costs of ABT. This will be the first long-term PS matched analysis to report on the clinical outcomes of SBT and affirms the clinical role of SBT in MSTS today.

AB075. When would minimally invasive spinal surgery not be preferable for metastatic spine disease?-a narrative review.

BACKGROUND: Metastatic spine tumour surgery (MSTS) is an important treatment modality of metastatic spinal disease (MSD). Open spine surgery (OSS) was previously the gold standard of treatment. However, advancements in MSTS in recent years has resulted in a current paradigm shift towards today's gold standard of minimally invasive spinal surgery (MISS) and early adjuvant RT in treating MSD patients. Nonetheless, there are still certain situations whereby MISS is not desirable or even suitable. There has also yet to be any literature describing the considerations for not using MISS in MSD in today's clinical context. We aim to bridge the gap where OSS should be considered with caution and highlight situations where MISS is preferable using the available literature and personal experience. METHODS: This narrative review was conducted using PubMed, Medical Literature Analysis and Retrieval System Online (MEDLINE), The Cochrane Library and Scopus databases through August 31, 2023. Inclusion criteria for the review were studies with discussion on the type of surgery in MSTS. RESULTS: A total of 52 studies were included in this review. We discussed various advantages and situations appropriate for MISS for MSD in today's clinical context. Nonetheless, there are still various unique circumstances in which MISS may be less suitable. MISS is less feasible in patients of paediatric profile, having short stature or having had previous surgery at the level of operation. Occipitocervical and cervicothoracic location of vertebrae metastasis also makes MISS less feasible due to access and imaging difficulty. MISS for tumours which are hypersclerotic and hypervascular can also result in more difficulty for cannulation of MISS probes as well as control of bleeding respectively, and hence will be less encouraged in the above settings. CONCLUSIONS: Our review will be the first to discuss circumstances in which MISS is less applicable, despite the advantages it may confer over traditional OSS. MSTS should be individualized to the patient, depending on the experience of the surgeon. OSS is still a time-tested approach that holds weight in MSTS and should be readily utilized depending on the clinical situation.

AB078. Patterns of treatment delay in patients with symptomatic metastatic epidural spinal cord compression.

BACKGROUND: Delayed treatment in symptomatic metastatic epidural spinal cord compression (MESCC) is significantly associated with poorer functional outcomes. In this study, we aim to identify the patterns of treatment delay in patients and factors predictive of postoperative ambulatory function. METHODS: Retrospective review of patients with symptomatic MESCC treated surgically between January 2015 and January 2022. MESCC symptoms were categorized into symptoms suggesting cord compression requiring immediate referral and symptoms suggestive of spinal metastases. Multivariate analysis was performed to identify factors predictive of postoperative ambulatory function. Delays in treatment were identified and categorized into patient delay (onset of symptoms till initial medical consultation), diagnostic delay (medical consultation till radiological diagnosis of MESCC), referral delay (from diagnosis till spine surgeon review) and surgical delay (from spine surgeon review till surgery) and compared between patients. RESULTS: One hundred and seventy-eight patients were identified. In this cohort 92 (52.0%) patients were able to ambulate independently, and 86 (48.3%) patients were non independent. One hundred and thirty-nine (78.1%) of patients had symptoms of cord compression and 93 (52.3%) had neurological deficits on presentation. On multivariate analysis, pre-operative neurological deficits (P=0.01) and symptoms of cord compression (P=0.01) were significantly associated with post-operative ambulatory function. Mean total delay was 66 days, patient delay was 41 days, diagnostic delay was 16 days, referral delay was 3 days and surgical delay was 6 days. In patients with neurological deficits, there was a significant decrease in all forms of treatment delay (P<0.05). There was no significant decrease in patient delay, diagnostic delay and referral delay in patients with symptoms of cord compression. CONCLUSIONS: Both patients and physicians understand the need for urgent surgical treatment of MESCC with neurological deficits, however there is still a need for increased education and recognition of the symptoms of MESCC.

AB081. Experience using CFR-PEEK implants in metastatic and primary spine tumour surgery: a single centre retrospective study.

BACKGROUND: Titanium has been the conventional implant material of choice for fixation in both primary and metastatic spine tumour surgeries (MSTS). However, these implants result in artefact generation during post-operative computed tomography (CT) or magnetic resonance imaging (MRI), resulting in poor planning of radiotherapy (RT) and suboptimal tumour surveillance. Carbon fibre-reinforced polyetheretherketone (CFR-PEEK) implants have gained momentum for instrumentation in MSTS due to their radiolucent properties. This in turn does not sacrifice the biomechanical strength of the implants. In this study, we compared the peri-operative outcomes, post operative imaging artefacts and dosimetricdata of CFR-PEEK implants to titanium implants to asses for potential benefits in post-operative RT planning in patients who underwent MSTS. METHODS: This is a retrospective study involving 42 patients operated for MSTS. Patient-related data including demographics, tumour pathology, intra-operative data, functional outcome, and RT-related data were collected for both groups. All patients were followed-up post-operatively for a minimum of 2 years or until demise, whichever was earlier. RESULTS: In our study, 20 (47.6%) patients had CFR-PEEK implants, while 22 (52.4%) of patients had titanium implants used for MSTS. Both groups of patients had similar clinical outcomes for pain and overall survival predictability pre-operatively (P>0.05). Mean number of levels instrumented by titanium screws were 6.8±2.93, while for the CFR-PEEK screws were 4.07±1.05. Mean volume of artefact generated during post operative CT was 75.1±43.4 mm3 in titanium group and 13.3±14.2 mm3 in CFR-PEEK group (P=0.005). The mean time taken to contour the artefacts was 17.3±5.84 minutes in the titanium group, while the CFR-PEEK group took 9.60±7.17 minutes (P=0.049). CONCLUSIONS: Our study suggests that carbon fibre reinforced PEEK screws significantly reduce artefact generation and the time taken to contour them during post-operative RT planning, while delivering equivalent clinical and functional outcomes as compared to standard titanium implants.

AB077. An evaluation of prognostic scoring systems for survival in a surgically treated cohort of 318 metastatic spine tumour surgery patients.

BACKGROUND: Survival prognostication plays a key role in the decision-making process for the surgical treatment of patients with spinal metastases. In the past traditional scoring systems such as the modified Tokuhashi and Tomita scoring systems have been used extensively, however in recent years their accuracy has been called into question. This has led to the development of machine learning algorithms to predict survival. In this study, we aim to compare the accuracy of prognostic scoring systems in a surgically treated cohort of patients. METHODS: This is a retrospective review of 318 surgically treated spinal metastases patients between 2009 and 2021. The primary outcome measured was survival from the time of diagnosis. Predicted survival at 3 months, 6 months and 1 year based on the prognostic scoring system was compared to actual survival. Predictive values of each scoring system were measured via area under receiver operating characteristic curves (AUROC). The following scoring systems were compared, Modified Tokuhashi (MT), Tomita (T), Modified Bauer (MB), Van Den Linden (VDL), Oswestry (O), New England Spinal Metastases score (NESMS), Global Spine Study Tumor Group (GSTSG) and Skeletal Oncology Research Group (SORG) scoring systems. RESULTS: For predicting 3 months survival, the GSTSG 0.980 (0.949-1.0) and NESM 0.980 (0.949-1.0) had outstanding predictive value, while the SORG 0.837 (0.751-0.923) and O 0.837 (0.775-0.900) had excellent predictive value. While for 6 months survival, only the O 0.819 (0.758-0.880) had excellent predictive value and the GSTSG 0.791(0.725-0.857) had acceptable predictive value. For 1 year survival, the NESM 0.871 (0.822-0.919) had excellent predictive value and the O 0.722 (0.657-0.786) had acceptable predictive value. The MT, T and MB scores had an area under the curve (AUC) of <0.5 for 3-month, 6-month and 1-year survival. CONCLUSIONS: Increasingly, traditional scoring systems such as the MT, T and MB scoring systems have become less predictive. While newer scoring systems such as the GSTSG, NESM and SORG have outstanding to excellent predictive value, there is no one survival scoring system that is able to accurately prognosticate survival at all 3 time points. A multidisciplinary, personalised approach to survival prognostication is needed.

Applications of Artificial Intelligence and Machine Learning in Spine MRI.

Diagnostic imaging, particularly MRI, plays a key role in the evaluation of many spine pathologies. Recent progress in artificial intelligence and its subset, machine learning, has led to many applications within spine MRI, which we sought to examine in this review. A literature search of the major databases (PubMed, MEDLINE, Web of Science, ClinicalTrials.gov) was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The search yielded 1226 results, of which 50 studies were selected for inclusion. Key data from these studies were extracted. Studies were categorized thematically into the following: Image Acquisition and Processing, Segmentation, Diagnosis and Treatment Planning, and Patient Selection and Prognostication. Gaps in the literature and the proposed areas of future research are discussed. Current research demonstrates the ability of artificial intelligence to improve various aspects of this field, from image acquisition to analysis and clinical care. We also acknowledge the limitations of current technology. Future work will require collaborative efforts in order to fully exploit new technologies while addressing the practical challenges of generalizability and implementation. In particular, the use of foundation models and large-language models in spine MRI is a promising area, warranting further research. Studies assessing model performance in real-world clinical settings will also help uncover unintended consequences and maximize the benefits for patient care.

Towards geospatially-resolved public-health surveillance via wastewater sequencing.

Wastewater is a geospatially- and temporally-linked microbial fingerprint of a given population, making it a potentially valuable tool for tracking public health across locales and time. Here, we integrate targeted and bulk RNA sequencing (N = 2238 samples) to track the viral, bacterial, and functional content over geospatially distinct areas within Miami Dade County, USA, from 2020-2022. We used targeted amplicon sequencing to track diverse SARS-CoV-2 variants across space and time, and we found a tight correspondence with positive PCR tests from University students and Miami-Dade hospital patients. Additionally, in bulk metatranscriptomic data, we demonstrate that the bacterial content of different wastewater sampling locations serving small population sizes can be used to detect putative, host-derived microorganisms that themselves have known associations with human health and diet. We also detect multiple enteric pathogens (e.g., Norovirus) and characterize viral diversity across sites. Moreover, we observed an enrichment of antimicrobial resistance genes (ARGs) in hospital wastewater; antibiotic-specific ARGs correlated to total prescriptions of those same antibiotics (e.g Ampicillin, Gentamicin). Overall, this effort lays the groundwork for systematic characterization of wastewater that can potentially influence public health decision-making.

Synthesis and Anticancer Activity of 3,4-Diaryl-1,2-dihydro- and 1,2,3,4-Tetrahydroquinolines.

Tetrahydroquinolines are key structures in a variety of natural products with diverse pharmacological utilities and other applications. A series of 3,4-diaryl-5,7-dimethoxy-1,2,3,4-tetrahydroquinolines were synthesized in good yield by reacting 3-aryl-5,7-dimethoxy-2,3-dihydroquinolin-4-ones with different Grignard reagents followed by the dehydration of the intermediate phenolic compounds. Subsequent reduction and deprotection were carried out to achieve the desired tetrahydroquinolone moiety. The lead compound 3c showed low micromolar inhibition of various cancer cell lines. Demethylation under different reaction conditions was also investigated to afford the corresponding monohydroxy analogues.

Expanding the cyanobacterial flora of India: Multiple novel species of Nostoc and Desmonostoc from Jammu and Kashmir, India using a polyphasic approach.

This investigation reports the polyphasic characterization of six cyanobacterial strains that were isolated from Basantgarh village of district Udhampur in the union territory of Jammu and Kashmir, India. Morphological examination of the isolated strains indicated that the strains are members of the genus Nostoc or its morphotypes. Phylogenetic analyses using the 16S rRNA gene showed that five strains clustered in the Nostoc sensu stricto clade, whereas one strain clustered in the Desmonostoc clade. Further, comparative studies with their phylogenetically related taxa, based on morphology, folded secondary structures, phylogeny of the ITS rRNA region, and the percent genetic homology of 16S rRNA gene and ITS rRNA region clearly established the strains as novel taxa belonging to the genera Nostoc and Desmonostoc. Also, two strains 21A-PS and 2JNA-PS emerged as conspecific to each other, representing the same species of Nostoc. Hence, in accordance with the International code of Nomenclature for algae, fungi, and plants, this study describes Nostoc jammuense, Nostoc globosum, Nostoc breve, and Nostoc coriaceum, as novel species of the genus Nostoc, while Desmonostoc raii is described as a novel species of the genus Desmonostoc. This study adds novel species of Nostoc from Indian habitats and reinforces the need to explore the Nostoc sensu stricto clade for more novel taxa.

Elucidating morphogenic and physiological traits of rice with nitrogen substitution through nano-nitrogen under salt stress conditions.

BACKGROUND: Sustainable crop production along with best nutrient use efficiency is the key indicator of smart agriculture. Foliar application of plant nutrients can complement soil fertilization with improved nutrient uptake, translocation and utilization. Recent developments in slow releasing, nano-fertilizers in agriculture, begins a new era for sustainable use and management of natural resources. This study aims to explore the effectiveness of nano-nitrogen usage on plant growth, yield attributes and sustaining rice production while optimizing fertilizer N application through conventional (prilled urea) and nano-N source under salt stress conditions. RESULTS: The strategic substitutions of traditional urea by nano-nitrogen was distributed from partial to complete with 33, 50, 66 and 100% applications. Further, the strategic substitutions were compared in saline (ECe ∼ 6.0 dSm- 1) and sodic stress (pH ∼ 9.1) conditions along with normal soils to dissect the beneficial response of nano-N in two rice varieties (CSR 30 and PB 1121). Salt stress affected the plant performance by decreasing leaf relative water content upto 10%, total chlorophyll content by 1.3-1.5%, leaf area upto 29.9%, gas exchange attributes by 10-39%, with concomitant yield reductions upto ∼ 4%. Collateral improvement in leaf greenness (SPAD index) crop growth rate and net assimilation rate was observed with foliar application of Nano-N. 0.2-1.64% enhancement in growth traits, 0.93-1.85% in physiological traits, and comparable yield gains with 100% recommended dose of prilled were comparative with nano-substitutions. Salt tolerant rice variety, CSR-30 performed better than PB 1121 with better expression of morphological, physiological and yield traits under stress conditions and nitrogen substitutions. CONCLUSIONS: Overall, our experimental findings revealed agricultural use of nano-N in improving the plant physiological efficiency and optimizing rice yields with partial N substitution through nano fertilizers under salt stress conditions. These studies are further open for futuristic aspects of long term effects of nano-fertilizers on soil nutrient depletion in correlation to yield enhancement in salt affected soils.

Oncologic Applications of Artificial Intelligence and Deep Learning Methods in CT Spine Imaging-A Systematic Review.

In spinal oncology, integrating deep learning with computed tomography (CT) imaging has shown promise in enhancing diagnostic accuracy, treatment planning, and patient outcomes. This systematic review synthesizes evidence on artificial intelligence (AI) applications in CT imaging for spinal tumors. A PRISMA-guided search identified 33 studies: 12 (36.4%) focused on detecting spinal malignancies, 11 (33.3%) on classification, 6 (18.2%) on prognostication, 3 (9.1%) on treatment planning, and 1 (3.0%) on both detection and classification. Of the classification studies, 7 (21.2%) used machine learning to distinguish between benign and malignant lesions, 3 (9.1%) evaluated tumor stage or grade, and 2 (6.1%) employed radiomics for biomarker classification. Prognostic studies included three (9.1%) that predicted complications such as pathological fractures and three (9.1%) that predicted treatment outcomes. AI's potential for improving workflow efficiency, aiding decision-making, and reducing complications is discussed, along with its limitations in generalizability, interpretability, and clinical integration. Future directions for AI in spinal oncology are also explored. In conclusion, while AI technologies in CT imaging are promising, further research is necessary to validate their clinical effectiveness and optimize their integration into routine practice.

Effect of Oxidation on Vivianite Dissolution Rates and Mechanism.

The interest in the mineral vivianite (Fe3(PO4)2·8H2O) as a more sustainable P resource has grown significantly in recent years owing to its efficient recovery from wastewater and its potential use as a P fertilizer. Vivianite is metastable in oxic environments and readily oxidizes. As dissolution and oxidation occur concurrently, the impact of oxidation on the dissolution rate and mechanism is not fully understood. In this study, we disentangled the oxidation and dissolution of vivianite to develop a quantitative and mechanistic understanding of dissolution rates and mechanisms under oxic conditions. Controlled batch and flow-through experiments with pristine and preoxidized vivianite were conducted to systematically investigate the effect of oxidation on vivianite dissolution at various pH-values and temperatures. Using X-ray absorption spectroscopy and scanning transmission X-ray microscopy techniques, we demonstrated that oxidation of vivianite generated a core-shell structure with a passivating oxidized amorphous Fe(III)-PO4 surface layer and a pristine vivianite core, leading to diffusion-controlled oxidation kinetics. Initial (<1 h) dissolution rates and concomitant P and Fe release (∼48 h) decreased strongly with increasing degree of oxidation (0-≤ 100%). Both increasing temperature (5-75 °C) and pH (5-9) accelerated oxidation, and, consequently, slowed down dissolution kinetics.

Two new species of Dulcicalothrix (Nostocales, Cyanobacteria) from India and erection of Brunnivagina gen. nov., with observations on the problem of using multiple ribosomal operons in cyanobacterial taxonomy.

Two new species of Dulcicalothrix, D. adhikaryi sp. nov. and D. iyengarii sp. nov., were discovered in India and are characterized and described in accordance with the rules of the International Code of Nomenclature for algae, fungi, and plants (ICN). As a result of phylogenetic analysis, Calothrix elsteri is reassigned to Brunnivagina gen. nov. During comparison with all Dulcicalothrix for which sequence data were available, we observed that the genus has six ribosomal operons in three orthologous types. Each of the three orthologs could be identified based upon indels occurring in the D1-D1' helix sequence in the ITS rRNA region between the 16S and 23S rRNA genes, and in these three types, there were operons containing ITS rRNA regions with and without tRNA genes. Examination of complete genomes in Dulcicalothrix revealed that, at least in the three strains for which complete genomes are available, there are five ribosomal operons, two with tRNA genes and three with no tRNA genes in the ITS rRNA region. Internal transcribed spacer rRNA regions have been consistently used to differentiate species, both on the basis of secondary structure and percent dissimilarity. Our findings call into question the use of ITS rRNA regions to differentiate species in the absence of efforts to obtain multiple operons of the ITS rRNA region through cloning or targeted PCR amplicons. The ITS rRNA region data for Dulcicalothrix is woefully incomplete, but we provide herein a means for dealing with incomplete data using the polyphasic approach to analyze diverse molecular character sets. Caution is urged in using ITS rRNA data, but a way forward through the complexity is also proposed.

Enhancing bone repair through improved angiogenesis and osteogenesis using mesoporous silica nanoparticle-loaded Konjac glucomannan-based interpenetrating network scaffolds.

We have fabricated and characterized novel bioactive nanocomposite interpenetrating polymer network (IPN) scaffolds to treat bone defects by loading mesoporous silica nanoparticles (MSNs) into blends of Konjac glucomannan, polyvinyl alcohol, and polycaprolactone. By loading MSNs, we developed a porous nanocomposite scaffold with mechanical strengths comparable to cancellous bone. In vitro cell culture studies proved the cytocompatibility of the nanocomposite scaffolds. RT-PCR studies confirmed that these scaffolds significantly upregulated major osteogenic markers. The in vivo chick chorioallantoic membrane (CAM) assay confirmed the proangiogenic activity of the nanocomposite IPN scaffolds. In vivo studies were performed using Wistar rats to evaluate the scaffolds' compatibility, osteogenic activity, and proangiogenic properties. Liver and renal function tests confirmed that these scaffolds were nontoxic. X-ray and µ-CT results show that the bone defects treated with the nanocomposite scaffolds healed at a much faster rate compared to the untreated control and those treated with IPN scaffolds. H&E and Masson's trichrome staining showed angiogenesis near the newly formed bone and the presence of early-stage connective tissues, fibroblasts, and osteoblasts in the defect region at 8 weeks after surgery. Hence, these advantageous physicochemical and biological properties confirm that the nanocomposite IPN scaffolds are ideal for treating bone defects.