A Review of Machine Learning Algorithms for Biomedical Applications

As the amount and complexity of biomedical data continue to increase, machine learning methods are becoming a popular tool in creating prediction models for the underlying biomedical processes. Although all machine learning methods aim to fit models to data, the methodologies used can vary greatly and may seem daunting at first. A comprehensive review of various machine learning algorithms per biomedical applications is presented. The key concepts of machine learning are supervised and unsupervised learning, feature selection, and evaluation metrics. Technical insights on the major machine learning methods such as decision trees, random forests, support vector machines, and k-nearest neighbors are analyzed. Next, the dimensionality reduction methods like principal component analysis and t-distributed stochastic neighbor embedding methods, and their applications in biomedical data analysis were reviewed. Moreover, in biomedical applications predominantly feedforward neural networks, convolutional neural networks, and recurrent neural networks are utilized. In addition, the identification of emerging directions in machine learning methodology will serve as a useful reference for individuals involved in biomedical research, clinical practice, and related professions who are interested in understanding and applying machine learning algorithms in their research or practice.

Extraction of Natural Pigment Curcumin from Curcuma Longa: Spectral, DFT, Third-order Nonlinear Optical and Optical Limiting Study

Herein, we report the extraction of natural pigment curcumin from curcuma longa and their linear and third-order nonlinear optical (NLO) characteristics. The characterization techniques viz., UV-Visible absorption, FT-IR, Micro Raman and Gas Chromatography Mass Spectrum (GC-MS) are used to study the spectral characteristics of curcumin. Third-order NLO features of curcumin are studied using Z‒scan technique with a semiconductor diode laser working at 405 nm wavelength. The natural pigment exhibits negative nonlinear index of refraction resulting from self-defocusing and positive coefficient of absorption is the consequence of reverse saturable absorption (RSA). The order of nonlinear index of refraction (n2) and nonlinear coefficient of absorption (β) is measured to be 10-7 cm2/W and 10-2 cm/W, respectively. Third-order NLO susceptibility (χ(3)) and second-order hyperpolarizability (γ) of curcumin is measured to be 2.73 × 10‒7 esu and 1.67 × 10‒31 esu, respectively. A low optical limiting (OL) threshold of 0.71 mW is observed in the extracted pigment. The experimental results are supplemented by quantum mechanical calculations of the NLO parameters. The overall result finding is that curcumin extracted from curcuma longa has the potential to be novel optical candidates for photonics and optoelectronics applications.

An intelligent fuzzy-particle swarm optimization supervisory-based control of robot manipulator for industrial welding applications

The propensity of manufacturers to produce goods at affordable cost, with more accuracy, and at a faster rate force them to search for novel solutions, such as deploying robots in place of people in a sector that can accommodate their needs. Welding is one of the most crucial processes in the automotive industry. This process is time-consuming, subject to error, and demands skilled professionals. The robotic application can improve this area of production and quality. Other industries, such as painting and material handling, can also profit from the use of robots. This work describes the fuzzy DC linear servo controller, which functions as a robotic arm actuator. Robots have been widely employed in most productive sectors in recent years, including assembly plates, welding, tasks at higher temperatures, etc. Controlling a robot accurately is a difficult undertaking as a robot is very nonlinear with many joints that are often organized and unstructured. To carry out the effective task, an effective PID control based on fuzzy logic has been employed together with the method of Particle Swarm Optimization (PSO) approach for the estimate of the parameter. This offline technique determines the lowest number of optimal robotic arm control parameters. To verify the controller design with computer simulation, a comparative assessment of controllers is given by means of a fuzzy surveillance controller with PSO which improves the parameter gain to provide a rapid climb, a smaller overflow, no steady condition error signal, and effective torque control of the robot arm.

Performance Analysis of Radial Basis Function Metamodels for Predictive Modelling of Laminated Composites

High-fidelity structural analysis using numerical techniques, such as finite element method (FEM), has become an essential step in design of laminated composite structures. Despite its high accuracy, the computational intensiveness of FEM is its serious drawback. Once trained properly, the metamodels developed with even a small training set of FEM data can be employed to replace the original FEM model. In this paper, an attempt is put forward to investigate the utility of radial basis function (RBF) metamodels in the predictive modelling of laminated composites. The effectiveness of various RBF basis functions is assessed. The role of problem dimensionality on the RBF metamodels is studied while considering a low-dimensional (2-variable) and a high-dimensional (16-variable) problem. The effect of uniformity of training sample points on the performance of RBF metamodels is also explored while considering three different sampling methods, i.e., random sampling, Latin hypercube sampling and Hammersley sampling. It is observed that relying only on the performance metrics, such as cross-validation error that essentially reuses training samples to assess the performance of the metamodels, may lead to ill-informed decisions. The performance of metamodels should also be assessed based on independent test data. It is further revealed that uniformity in training samples would lead towards better trained metamodels.

Efficacy of various intracanal medicaments against aerobic and facultative anaerobic microorganism found in human primary teeth with necrotic pulp: A randomized clinical trial

AIM

The aim of this in vivo study is to evaluate the antimicrobial efficacy of calcium hydroxide (Ca(OH)₂), chlorhexidine (CHX), and metronidazole gel as intracanal medicaments against aerobic and facultative anaerobic microorganisms found in root canals of human primary teeth with necrotic pulp.

SETTING AND DESIGN

It is a double-blinded randomized clinical trial.

MATERIALS AND METHODS

Pulp canals of 45 single-rooted primary maxillary anterior teeth with pulp necrosis in 34 children were included in the study. They were divided into three groups of 15 samples each: Group I: Ca(OH)₂; Group II: 1% CHX gel; and Group III: 1% metronidazole gel. Microbial count was obtained from each tooth at two different stages - (1) after instrumentation and (2) after placement of the medication. Statistical analysis using the SPSS 10.0 software program (SPSS Inc., Chicago, IL, USA) with Wilcoxon signed-rank test after grouping the samples was performed.

RESULTS

Ca(OH)₂, 1% CHX gel, and 1% metronidazole gel were ineffective in completely eliminating aerobic and facultative anaerobic microorganism from root canal of human primary teeth with necrotic pulp.

CONCLUSION

None of the commonly used intracanal medicaments, that is Ca(OH)₂, 1% CHX gel, and 1% metronidazole gel, was effective in completely eliminating aerobic and facultative anaerobic microorganism from root canal of human primary teeth with necrotic pulp. Ineffectiveness of these medicaments against aerobic and facultative anaerobic microorganism has opened new door of research regarding the manner of bacterial growth in unfavorable environmental and nutritional conditions, the way root canal environment favors biofilm formation and the use of suitable intracanal medicaments against single and multispecies biofilms.

Association of Vitamin D Levels and type 2 Diabetes Mellitus in Asian Indians is Independent of Obesity

Background A large proportion of subjects with type 2 diabetes mellitus (T2DM) in India are non-obese. Asian-Indian subjects with diabetes have been shown to have low vitamin D levels. Whether low vitamin D levels and T2DM in Asian-Indians is attributable to the associated obesity as in caucasians is unclear. Hence we studied the association of vitamin D levels and T2DM in Asian-Indians with or without obesity.

Methods Total of 213 subjects were recruited in four groups, group 1-Non-obese diabetic, group 2-Non-obese non-diabetic, group 3-Obese diabetic and group 4-Obese non-diabetic. Subjects recruited under various groups were matched for age and sex. Anthropometry, skin-fold thickness, fasting and postprandial plasma glucose, HbA1c, fasting insulin, lipids and vitamin D levels were measured in all study subjects and were compared between the groups.

Results Mean age of study population was 41.23±7.43 years. Mean BMI in groups 1,2,3 and 4 was 21.34±1.41, 20.53±2.27, 27.72±2.94 and 27.62±3.37 kg/m2 respectively. Overall 64.3% study subjects had vitamin D deficiency and 27.7% had insufficient vitamin D levels. Significantly lower vitamin D levels were found in diabetic groups 1 and 3 compared to non-diabetic groups 2 and 4. No significant difference was observed in vitamin D levels between groups 1 and 3. Similarly, no significant difference was observed in vitamin D levels between groups 2 and 4. Vitamin D levels did not show any significant correlation with BMI, waist or body fat.

Conclusion Vitamin D levels do not appear to be related to obesity in diabetic as well non-diabetic Asian-Indian individuals.

Comparative study of CURB-65, Pneumonia Severity Index and IDSA/ATS scoring systems in community acquired pneumonia in an Indian tertiary care setting

Background: Few comparative studies regarding prognostic scoring systems for community acquired pneumonia (CAP) are available from Indian context.Methods: Hospital-based prospective study to test the comparison between confusion, urea, respiratory rate, blood pressure, age over 65 years (CURB-65), Pneumonia severity index (PSI) and infectious diseases society of America/American thoracic society criteria (IDSA/ATS) scoring systems in patients with community acquired pneumonia.Results: CURB-65 class ≥III, PSI class ≥IV and patients who needed admission to intensive care unit (ICU) based on IDSA/ATS criteria were having sensitivity of 41.7%, 91.7% and 87.5% in predicting ICU admission with a specificity of 89.5%, 59.2% and 73.7% respectively. Their sensitivity in predicting death were 44.4%, 88.9% and 83.3% with a specificity of 87.8%, 54.9% and 68.3% respectively. In both PSI score and IDSA/ATS criteria risk scoring systems, mortality rate, need for ICU admission increased progressively with increasing scores but CURB-65 score did not show this correlation. The PSI class ≥IV was more sensitive in predicting ICU admission than CURB-65 and IDSA/ATS criteria.Conclusions: PSI was most sensitive in both predicting ICU admission and death whereas CURB-65 is most specific in predicting ICU admission and death. But CURB-65 is least sensitive in both predicting ICU admission and death. Even though IDSA/ATS criteria did not have highest sensitivity and specificity as single criteria it had modest sensitivity and specificity in predicting ICU admission and death.

Bio-mimetic mineralization potential of collagen hydrolysate obtained from chromium tanned leather waste

Hydroxyapatite (HA) ceramics serve as an alternative to autogenous-free bone grafting by virtue of their excellent biocompatibility. However, chemically synthesized HA lacks the strong load-bearing capacity as required by bone. The bio-mimetic growth of HA crystals on collagen surface provides a feasible solution for synthesizing bone substitutes with the desired properties. This study deals with the utilization of the collagen hydrolysate recovered from leather waste as a substrate for promoting HA crystal growth. Bio-mimetic growth of HA was induced by subjecting the hydrolysate to various mineralization conditions. Parameters that would have a direct effect on crystal growth were varied to determine the optimal conditions necessary. Maximum mineralization was achieved with a combination of 10mM of CaCl2, 5mM of Na2HPO4, 100mM of NaCl and 0.575% glutaraldehyde at a pH of 7.4. The metal-protein interactions leading to formation of HA were identified through Fourier-transform infrared (FTIR) spectroscopy and x-ray diffraction (XRD) studies. The crystal dimensions were determined to be in the nanoscale range by atomic force microscopy (AFM) and scanning electron microscopy (SEM). The size and crystallinity of bio-mimetically grown HA indicate that hydrolysate from leather waste can be used as an ideal alternative substrate for bone growth.

The effect of dexmedetomidine continuous infusion as an adjuvant to general anesthesia on sevoflurane requirements: A study based on entropy analysis

Background:

Dexmedetomidine, a α2 agonist as an adjuvant in general anesthesia, has anesthetic and analgesic-sparing property.

Aims:

To evaluate the effect of continuous infusion of dexmedetomidine alone, without use of opioids, on requirement of sevoflurane during general anesthesia with continuous monitoring of depth of anesthesia by entropy analysis.

Materials and Methods:

Sixty patients were randomly divided into 2 groups of 30 each. In group A, fentanyl 2 mcg/kg was given while in group B, dexmedetomidine was given intravenously as loading dose of 1 mcg/kg over 10 min prior to induction. After induction with thiopentone in group B, dexmedetomidine was given as infusion at a dose of 0.2-0.8 mcg/kg. Sevoflurane was used as inhalation agent in both groups. Hemodynamic variables, sevoflurane inspired fraction (FI_sevo), sevoflurane expired fraction (ET_sevo), and entropy (Response entropy and state entropy) were continuously recorded. Statistical analysis was done by unpaired student's t-test and Chi-square test for continuous and categorical variables, respectively. A P-value < 0.05 was considered significant.

Results:

The use of dexmedetomidine with sevoflurane was associated with a statistical significant decrease in ET_sevo at 5 minutes post-intubation (1.49 ± 0.11) and 60 minutes post-intubation (1.11 ±0.28) as compared to the group A [1.73 ±0.30 (5 minutes); 1.68 ±0.50 (60 minutes)]. There was an average 21.5% decrease in ET_sevo in group B as compared to group A.

Conclusions:

Dexmedetomidine, as an adjuvant in general anesthesia, decreases requirement of sevoflurane for maintaining adequate depth of anesthesia.

Effect of intravenous infusion of dexmedetomidine on perioperative haemodynamic changes and postoperative recovery: A study with entropy analysis

Background:

Dexmedetomidine, an α2 agonist, when used as an adjuvant in general anaesthesia attenuates stress response to various noxious stimuli, maintains perioperative haemodynamic stability and provides sedation without significant respiratory depression postoperatively.

Methods:

Sixty patients were randomly divided into two groups of 30 each. In group A, fentanyl 2 μg/kg and in group B dexmedetomidine were given intravenously as loading dose of 1 μg/kg over 10 min prior to induction. After induction with thiopentone, in group B, dexmedetomidine was given as infusion at a dose of 0.2–0.8 μg/kg. Sevoflurane was used as inhalation agent in both groups. Haemodynamic variables and entropy (response entropy and state entropy) were recorded continuously. Postoperative sedation and recovery were assessed by sedation score and modified Aldrete's score, respectively.

Results:

Dexmedetomidine significantly attenuates stress response at intubation with lesser increase in heart rate (10% vs. 17%), systolic blood pressure (6% vs. 23%) and diastolic blood pressure (7% vs. 20%) as compared to the control group (P<0.05). Intraoperatively, an average of 8% fall in systolic blood pressure and 8.16% fall in diastolic pressure in the test group as compared to 3.6% rise in systolic and 3.3% in diastolic pressure of the control group was observed. Postoperatively, the test group showed significant sedation at 2 h as compared to the control group (P=0.00) and recovery was better in the control group for the first 2 h post extubation.

Conclusion:

Dexmedetomidine attenuates various stress responses during surgery and maintains the haemodynamic stability when used as an adjuvant in general anaesthesia. Also, the sedative action of dexmedetomidine delays recovery for the first few hours post extubation.

Early eruption of permanent canines

Systemic and local factors can modify the eruption time of teeth. Generalized eruption time changes could be due to some systemic diseases like hyperthyroidism, hypophosphatasia, precocious puberty, Proteus syndrome, etc. Localized early eruption of permanent teeth could be due to early extraction of deciduous teeth. Presented here is an extremely rare case of early eruption of permanent canines in a 7-year old female child. Though the number of such cases is very limited, the clinician should poses adequate knowledge and keeps an open eye to identify such cases.

Cecembia lonarensis gen. nov., sp. nov., a haloalkalitolerant bacterium of the family Cyclobacteriaceae , isolated from a haloalkaline lake and emended descriptions of the genera Indibacter , Nitritalea and Belliella

A novel Gram-staining-negative, rod-shaped, non-motile bacterium, designated strain LW9T, was isolated from a water sample collected from Lonar Lake of Buldhana district, Maharashtra, India. Colonies and broth cultures were reddish orange due to the presence of carotenoid pigments. Strain LW9T was positive for catalase, ornithine decarboxylase and lysine decarboxylase activities and negative for gelatinase, oxidase, urease and lipase activities. The predominant fatty acids were iso-C15 : 0 (31.3 %), iso-C16 : 0 (9.3 %), anteiso-C15 : 0 (7.3 %), iso-C16 : 1 H (6.1 %), summed feature 3 (comprising C16 : 1ω7c/C16 : 1ω6c; 5.9 %), iso-C17 : 1ω9c (5.4 %) and iso-C17 : 0 3-OH (5.0 %). Strain LW9T contained MK-7 as the major respiratory quinone. The polar lipids consisted of phosphatidylethanolamine, two unidentified aminolipids and seven unidentified lipids. The DNA G+C content of strain LW9T was 40.5 mol%. 16S rRNA gene sequence analysis indicated that the type strains of Indibacter alkaliphilus and Aquiflexum balticum , two members of the family Cyclobacteriaceae (phylum ‘ Bacteroidetes ’) were the most closely related strains with sequence similarities of 93.0 and 94.0 %, respectively. Other members of the family Cyclobacteriaceae showed sequence similarities <93.0 %. Based on these phenotypic characteristics and on phylogenetic inference, strain LW9T is proposed as the representative of novel species in a new genus, Cecembia lonarensis gen. nov., sp. nov. The type strain of the type species, Cecembia lonarensis, is LW9T ( = CCUG 58316T = KCTC 22772T). Emended descriptions of the genera Indibacter , Nitritalea and Belliella are also proposed.

Lutibaculum baratangense gen. nov., sp. nov., a proteobacterium isolated from a mud volcano

A novel Gram-negative, oval to rod-shaped, motile bacterium, strain AMV1T, was isolated from a soil sample collected from a mud volcano of Baratang Island, Andamans, India. The predominant fatty acids were C16 : 0 (5.7 %), C18 : 1ω7c (78.6 %) and C19 : 0 cyclo ω8c (6.3 %). Strain AMV1T contained ubiquinone 10 (Q-10) as the major respiratory quinone and minor quantities of ubiquinone 9 (Q-9). The polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, three unidentified lipids, one unidentified phospholipid and one unidentified aminolipid. 16S rRNA gene sequence analysis indicated that strain AMV1T was related most closely to the type strains of Tepidamorphus gemmatus , Bauldia consociata , Afifella pfennigii and Amorphus coralli , four members of the order Rhizobiales (class Alphaproteobacteria ), with pairwise sequence similarities of 95.0, 94.5, 94.4 and 94.0 %, respectively; it shared <94 % 16S rRNA gene sequence similarity with all the other members of the order Rhizobiales . Phylogenetic analyses indicated that strain AMV1T clustered with Tepidamorphus gemmatus and with species of the genera Amorphus , Rhodobium and Afifella . Phenotypic and phylogenetic characteristics thus suggest that strain AMV1T is a representative of a novel species of a new genus, for which the name Lutibaculum baratangense gen. nov., sp. nov. is proposed. The type strain of Lutibaculum baratangense is AMV1T ( = KCTC 22669T = NBRC 105799T = CCUG 58046T).

Lutibaculum baratangense gen. nov., sp. nov., a novel proteobacterium isolated from a mud volcano, Andamans, India

A novel Gram-negative, oval to rod shaped, motile bacterium, strain AMV1T, was isolated from a soil sample collected from a mud volcano, Baratang Island, Andamans, India. The fatty acids were dominated by unsaturated fatty acids (82.6 %), with a high presence of C18:1 ω7c (78.6 %). Strain AMV1T contained ubiquinone (Q9) and menaquinone (MK-4 and MK-8) as the respiratory quinones. The polar lipids consisted of four unknown aminolipids, two unknown glycoaminolipids and two unknown phospholipids. The 16S rRNA gene sequence analysis indicated that Amorphus coralli, Phyllobacterium myrsinacearum and Bauldia consociatum, three members of the order Rhizobiales (phylum Alphaproteobacteria) are the closest related species with pairwise sequence similarities of 94.0,94.0 and 94.5, % respectively and <94% with all the other members of the order Rhizobiales. Phylogenetic analyses indicated that strain AMV1T clustered with Amorphus coralli and branched separately from the members of the family Rhodobiaceae. Phenotypic and phylogenetic characteristics suggested that strain AMV1T is a representative of a novel genus and a new species, Lutibaculum baratangense gen. nov., sp. nov. The type strain is AMV1T (= KCTC 22669T = NBRC 105799T = CCUG 58046T).

Nitritalea halalkaliphila gen. nov., sp. nov., an alkaliphilic bacterium of the family ‘Cyclobacteriaceae’, phylum Bacteroidetes

A novel Gram-negative, rod-shaped, non-motile bacterium, designated strain LW7T, was isolated from a water sample collected at a depth of 4.5 m from Lonar Lake in Buldhana district, Maharastra, India. The cell suspension was dark-reddish orange due to the presence of carotenoids. The fatty acids were dominated by large amounts of iso-C15 : 0 (59.6 %) and iso-C17 : 0 3-OH (8.9 %). Strain LW7T contained MK-4 and MK-5 as the major respiratory quinones and phosphatidylglycerol and phosphatidylethanolamine as the major phospholipids. 16S rRNA gene sequence analysis indicated that Belliella baltica, a member of family ‘Cyclobacteriaceae’ (phylum Bacteroidetes), is the closest related species, with a sequence similarity of 94.0 % to the type strain. Other members of the family ‘Cyclobacteriaceae’ had sequence similarities of <93.3 %. Based on the above-mentioned phenotypic and phylogenetic characteristics, strain LW7T is proposed as a representative of a new genus and species, Nitritalea halalkaliphila gen. nov., sp. nov. The type strain of Nitritalea halalkaliphila is LW7T (=CCUG 57665T =JCM 15946T =NCCB 100279T). The genomic DNA G+C of strain LW7T is 49 mol%.

Cesiribacter andamanensis gen. nov., sp. nov., isolated from a soil sample from a mud volcano

A novel gram-staining-negative, rod-shaped, non-motile bacterium, strain AMV16(T), was isolated from a soil sample collected from a mud volcano located in the Andaman Islands, India. The cell suspension was pale orange. Cells of strain AMV16(T) were positive for catalase, oxidase, lipase, ornithine decarboxylase and lysine decarboxylase and negative for gelatinase and urease. The fatty acids present were anteiso-C(11 : 0) (5.4 %), anteiso-C(12 : 0) (4.1 %), C(12 : 0) (7.0 %), iso-C(15 : 0) (14.4 %), anteiso-C(15 : 0) (3.4 %), anteiso-C(16 : 0) (3.0 %), C(16 : 0) (2.6 %), anteiso-C(17 : 0) (3.7 %), iso-C(19 : 0) (9.7 %), C(13 : 1) (13.8 %), iso-C(15 : 1) G (15.9 %), iso-C(16 : 1) G (11.1 %) and summed feature 5 (anteiso-C(18 : 0) and/or C(18 : 2)ω6,9c; 5.9 %). Strain AMV16(T) contained MK-4 is [corrected] the major respiratory quinone and diphosphatidylglycerol and phosphatidylethanolamine made up the phospholipids. The G+C content of DNA of strain AMV16(T) was 50.9 mol%. blast sequence similarity searches based on the 16S rRNA gene sequence indicated that species of the genus Marivirga were the nearest phylogenetic neighbours, with pairwise sequence similarity ranging from 89.9 to 90.0 %. Phylogenetic analyses indicated that strain AMV16(T) clustered with the type strains of Marivirga tractuosa and Marivirga sericea at a phylogenetic distance of 14.6 % (85.4 % similarity), distinct from clades representing other genera of the family 'Flammeovirgaceae'. Based on the above-mentioned phenotypic and phylogenetic characteristics, strain AMV16(T) is proposed as a representative of a new genus and novel species, Cesiribacter andamanensis gen. nov., sp. nov. The type strain of Cesiribacter andamanensis is AMV16(T) ( = DSM 22818(T)  = CCUG 58431(T)).

Indibacter alkaliphilus gen. nov., sp. nov., an alkaliphilic bacterium isolated from a haloalkaline lake

A novel Gram-stain-negative, rod-shaped, non-motile bacterium, strain LW1(T), was isolated from a water sample collected at a depth of 3.5 m from Lonar Lake, Buldhana district, Maharashtra, India. The cell suspension was reddish-orange due to the presence of carotenoids. Strain LW1(T) was positive for catalase, oxidase, ornithine decarboxylase and lysine decarboxylase and negative for gelatinase, urease and lipase. Fatty acids were dominated by branched-chain fatty acids (>76 %), with a high abundance of iso-C(15 : 0) (48 %), anteiso-C(15 : 0) (7 %) and iso-C(17 : 0) 3-OH (11 %). Strain LW1(T) contained MK-4 and MK-7 as the major respiratory quinones and phosphatidylglycerol, phosphatidylcholine and phosphatidylethanolamine as the major phospholipids. A blast sequence similarity search based on 16S rRNA gene sequences indicated that members of the genera Belliella and Aquiflexum were the nearest phylogenetic neighbours with similarities of 91.8-92.3 %. Phylogenetic analyses indicated that strain LW1(T) formed a deep-rooted lineage distinct from the clades represented by the genera Belliella, Aquiflexum, Cyclobacterium, Echinicola and Algoriphagus. Based on the above-mentioned phenotypic and phylogenetic characteristics, it is proposed that strain LW1(T) represents a novel species in a new genus, Indibacter alkaliphilus gen. nov., sp. nov. (type strain LW1(T)=KCTC 22604(T)=CCUG 57479(T)). The genomic DNA G+C content of strain LW1(T) is 42.7+/-1 mol%.

Indibacter alkaliphilus gen. nov., sp. nov., an alkaliphilic bacterium isolated from a haloalkaline lake

A novel Gram-stain-negative, rod-shaped, non-motile bacterium, strain LW1T, was isolated from a water sample collected at a depth of 3.5 m from Lonar Lake, Buldhana district, Maharashtra, India. The cell suspension was reddish-orange due to the presence of carotenoids. Strain LW1T was positive for catalase, oxidase, ornithine decarboxylase and lysine decarboxylase and negative for gelatinase, urease and lipase. Fatty acids were dominated by branched-chain fatty acids (>76 %), with a high abundance of iso-C15 : 0 (48 %), anteiso-C15 : 0 (7 %) and iso-C17 : 0 3-OH (11 %). Strain LW1T contained MK-4 and MK-7 as the major respiratory quinones and phosphatidylglycerol, phosphatidylcholine and phosphatidylethanolamine as the major phospholipids. A blast sequence similarity search based on 16S rRNA gene sequences indicated that members of the genera Belliella and Aquiflexum were the nearest phylogenetic neighbours with similarities of 91.8–92.3 %. Phylogenetic analyses indicated that strain LW1T formed a deep-rooted lineage distinct from the clades represented by the genera Belliella, Aquiflexum, Cyclobacterium, Echinicola and Algoriphagus. Based on the above-mentioned phenotypic and phylogenetic characteristics, it is proposed that strain LW1T represents a novel species in a new genus, Indibacter alkaliphilus gen. nov., sp. nov. (type strain LW1T=KCTC 22604T=CCUG 57479T). The genomic DNA G+C content of strain LW1T is 42.7±1 mol%.

Cathodic behaviour of stainless steel in coastal Indian seawater: calcareous deposits overwhelm biofilms

Type-316 stainless steel (SS) was investigated as the cathode in galvanic couples in full-strength seawater from the Gulf of Mannar on the southeast coast of India. Tests were devised to examine the impact of SS cathodes on anode materials with or without the accrual of marine biofilms. Biofilmed SS cathodes significantly enhanced the rate of corrosion of nickel, causing noble shifts in the couple potentials. With mild steel and zinc as the anodes, calcareous deposits developed quite rapidly on the SS cathodes and led to a significant reduction of bacterial numbers. The calcareous deposits also caused substantial reduction of galvanic corrosion rates for mild steel, whereas there was no difference for zinc. The deposits were identified by XRD as essentially carbonates, oxides and hydroxides of calcium and magnesium. Potentiodynamic polarization performed on the actual couples after disconnection and equilibration provided reasonable interpretations of the galvanic corrosion trends. Data from this work suggest that a potential of about -0.70 V vs. saturated calomel electrode (SCE) should provide optimum protection of SS in warmer, full-strength seawater that supports the precipitation of calcareous deposits. The criterion commonly recommended for temperate conditions of lower water temperature and estuarine waters of lower alkalinity is -1.0 V (SCE).

Templated synthesis of silver nanowires based on the layer-by-layer assembly of silver with dithiodipropionic acid molecules as spacers

The layer-by-layer assembly of silver nanoclusters with 3,3'-dithiodipropionic acid (DTDPA) as spacers was prepared through self-assembly on a gold foil and has been characterized by cyclic voltammetric and AFM techniques. The DTDPA molecules acting as spacers between the layers of silver serve as molecular interconnects for the four layers prepared in this work. The organization of layers was found to decrease with an increase in the number of layers. The layer-by-layer assembly of silver clusters motivated us to prepare silver nanowires stabilized by the bifunctional molecules DTDPA through template synthesis using cellulose nitrate membranes. The nanostructures formed by this method were characterized by SEM, TEM, AFM, FTIR, CV, and photoluminescence studies. It is observed that the DTDPA molecules, instead of forming molecular interconnects, protect the structures by self-assembling themselves along the edges of the nanostructures. The concept of self-assembly protecting the nanostructures is demonstrated in this work.

The developmental stages of the middle phalanx of the third finger (MP3): a sole indicator in assessing the skeletal maturity?

Assessment of skeletal maturity is an integral part of interceptive diagnosis and treatment planning. The present day methods of skeletal maturity assessment like the hand-wrist radiographs or cervical vertebrae radiographs are expensive, require elaborate equipment and accounts for high radiation exposure, especially for growing children. The present study was thus undertaken to provide a simple and practical method of skeletal maturity assessment using the developmental stages of the middle phalanx of the third finger (MP3) as seen on an IOPA film taken using a standard dental x-ray machine. The results of the study showed that this simple method was highly reliable and could be used as an alternative method to assess the skeletal maturity of growing children.

Angle scintillations in the laser return from a retroreflector

Angle scintillations of the laser return from a retroreflector were observed to exceed the value expected because of atmospheric turbulence. The observations and a theoretical analysis of a possible mechanism are presented. The experimental work was performed with a pulsed, 1.06-micro laser illuminating a corner cube. Angular scintillations of the laser return were measured to be eight times greater than that of a reference beacon. The theoretical analysis assumes phase fluctuations in the illuminating laser beam. An expression is derived for the scintillation angle as a function of a phase fluctuation parameter.