Response Surface Methodology Applied to the Enzymatic Synthesis of Galacto-oligosaccharides from Cheese Whey

Cristiane Reinaldo Lisboa,Luciana de Simoni Martinez,Renata Aguirre Trindade,Fátima Aparecida de Almeida Costa,Janaína Fernandes de Medeiros Burkert,Carlos André Veiga Burkert 한국식품과학회 2012 Food Science and Biotechnology Vol.21 No.6

In this study, a strategy was proposed for making galacto-oligossaccharides (GOS), a high valueadded product, from a byproduct of the dairy industry,cheese whey, using a commercial β-galactosidase from Kluyveromyces lactis (Lactozym® 3000L). The effects of the substrate concentration, temperature, and enzyme dosage were statistically studied and their optimum combinations were determined using response surface methodology. The increase in lactose concentration, temperature, and enzyme concentration favored a transgalactosylation reaction. The maximum values for GOS concentration (119.8 mg/mL)and yield (29.9%) in a 4 h process were obtained in the reaction system, composed of 400 mg/mL of lactose and 10 U/mL of enzyme at 40°C. Under these conditions, the lactose conversion was 68.7%. The maximum value for lactose conversion (87.8%) was observed at the same temperature and enzyme concentration, although the lactose level was 20%.

Extraction of Carotenoids from Phaffia rhodozyma: A Comparison between Different Techniques of Cell Disruption

Mariano Michelon,Thais de Matos de Borba,Ruan da Silva Rafael,Carlos André Veiga Burkert,Janaína Fernandes de Medeiros Burkert 한국식품과학회 2012 Food Science and Biotechnology Vol.21 No.1

The yeast Phaffia rhodozyma is known for producing carotenogenic pigments, commonly used in aquaculture feed formulation as well as in cosmetic,pharmaceutical, and food industries. Despite the high production of carotenoids from microorganisms by biotechnology, their use has limitation due to the cell wall resistance, which constitutes a barrier to the bioavailability of carotenoids. Therefore, there is a need to improve carotenoids recovering technique from microorganisms for the application of food industries. This study aimed to compare mechanical, chemical, and enzymatic techniques of cell disruption for extracting carotenoids produced by P. rhodozyma NRRL Y-17268. Among the techniques studied, the highest specific concentration of carotenoids (190.35 μg/g) resulted from the combined techniques of frozen biomass maceration using diatomaceous earth and enzymatic lysis at pH of the reaction medium of 4.5 at 55oC, with initial activity of β-1,3 glucanase of 0.6 U/mL for 30 min.

교회교육 지도자들을 위한 전문지 / 자료 : 학생들과 함께 하는 사역 - 학생들로 리더가 되게 하라 -

(Jana Sundene),(Dan Webster) 장로회신학대학교 기독교교육연구원 1986 교육교회 Vol.- No.119

A successive ionic layer adsorption and reaction (SILAR) method to fabricate a layer-by-layer (LbL) MnO₂-reduced graphene oxide assembly for supercapacitor application

Jana, Milan,Saha, Sanjit,Samanta, Pranab,Murmu, Naresh Chandra,Kim, Nam Hoon,Kuila, Tapas,Lee, Joong Hee Elsevier 2017 Journal of Power Sources Vol.340 No.-

<P><B>Abstract</B></P> <P>A facile, cost effective and additive-free successive ionic layer adsorption and reaction (SILAR) technique is demonstrated to develop layer-by-layer (LbL) assembly of reduced graphene oxide (RGO) and MnO<SUB>2</SUB> (MnO<SUB>2</SUB>-RGO<SUB>SILAR</SUB>) on a stainless steel current collector, for designing light-weight and small size supercapacitor electrode. The transmission electron microscopy and field emission scanning electron microscopy images shows uniform distribution of RGO and MnO<SUB>2</SUB> in the MnO<SUB>2</SUB>-RGO<SUB>SILAR</SUB>. The LbL (MnO<SUB>2</SUB>-RGO<SUB>SILAR</SUB>) demonstrates improved physical and electrochemical properties over the hydrothermally prepared MnO<SUB>2</SUB>-RGO (MnO<SUB>2</SUB>-RGO<SUB>Hydro</SUB>). The electrochemical environment of MnO<SUB>2</SUB>-RGO<SUB>SILAR</SUB> is explained by constant phase element in the high frequency region, and a Warburg element in the low frequency region in the Z-View fitted Nyquist plot. The equivalent circuit of the MnO<SUB>2</SUB>-RGO<SUB>Hydro</SUB>, displays the co-existence of EDL and constant phase element, indicating inhomogeneous distribution of MnO<SUB>2</SUB> and RGO by the hydrothermal technique. An asymmetric supercapacitor device is designed with MnO<SUB>2</SUB>-RGO<SUB>SILAR</SUB> as positive electrode, and thermally reduced GO (TRGO) as negative electrode. The designed cell exhibits high energy density of ∼88 Wh kg<SUP>−1</SUP>, elevated power density of ∼23,200 W kg<SUP>−1</SUP>, and ∼79% retention in capacitance after 10,000 charge-discharge cycles.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Layer-by-layer assembly (LbL) of MnO<SUB>2</SUB> and reduced graphene oxide (RGO) is prepared. </LI> <LI> The LbL acts as single material with hybrid electrochemical properties. </LI> <LI> Uniform distribution of MnO<SUB>2</SUB> over RGO exhibits high specific capacitance. </LI> <LI> No organic binder is used to design the supercapacitor electrodes. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>The LbL RGO-MnO<SUB>2</SUB> acts as single hybrid electro-active material and the hydrothermally prepared RGO-MnO<SUB>2</SUB> provides mixed properties of two materials.</P> <P>[DISPLAY OMISSION]</P>

Treatment of Symptomatic Focal Hepatic Hemangioma with Propranolol in Neonates: Is It Efficient?

Jana Lozar Krivec,Nina Lah,Mojca Glušič,Orjana Velikonja,Darja Paro-Panjan 대한소아소화기영양학회 2023 Pediatric gastroenterology, hepatology & nutrition Vol.26 No.1

Hepatic hemangiomas (HH) – classified into congenital hepatic hemangiomas (CHH) or infantile hepatic hemangiomas (IHH) – are benign vascular tumors that are mainly asymptomatic, but may cause clinical problems that require treatment. While focal, multifocal, and diffuse IHH are responsive to propranolol treatment, CHH is mainly focal and thought to be resistant to treatment with propranolol. The clinical and imaging distinctions between CHH and IHH in cases of focal lesions can be challenging, while histopathological distinction is mostly lacking in the clinical setting. We report 4 neonatal symptomatic cases of focal HH treated with propranolol, with partial or complete resolution of the tumor, and the positive hemodynamic effect of propranolol in one case. We believe that although clear differentiation cannot be achieved between CHH and IHH without histopathological examination in cases of focal HH in neonates, propranolol treatment should be attempted in symptomatic cases since its benefits outweigh the possible small risk of side effects of propranolol.

Linking Leaf Functional Traits with Plant Resource Utilization Strategy in an Evergreen Scrub Species Rhododendron caucasicum Pall. along Longitudinal Gradient in Georgia (The South Caucasus)

Jana Ekhvaia,Arsena Bakhia,Zezva Asanidze,Tornike Beltadze,Otar Abdaladze 강원대학교 산림과학연구소 2022 Journal of Forest Science Vol.38 No.2

Leaf functional traits widely have been used to understand the environmental controls of resource utilization strategy of plants along the environmental gradients. By using key leaf functional traits, we quantified the relationships between leaf traits and local climate throughout the distributional range of Rhododendron caucasicum Pall. in eastern and western Georgian mountains (the South Caucasus). Our results revealed, that all traits showed high levels of intraspecific variability across study locations and confirmed a strong phenotypic differentiation of leaf functional variation along the east-west longitudinal gradient in response to the local climate; out of the explored climatic variables, the moisture factors related to precipitation and number of precipitation and dry days for winter and growth seasons were more strongly related to leaf trait variation than the elevation and air temperature. Among studied leaf traits, the leaf specific area (SLA) showed the highest level of variability indicating the different resource utilization strategies of eastern and western-central Rh. caucasicum individuals. High SLA leaves for western-central Caucasian individuals work in relatively resource-rich environments (more humid in terms of precipitation amount and the number of precipitation days in winter) and could be explained by preferential allocation to photosynthesis and growth, while eastern Caucasian samples work in resource-poor environments (less humid in terms of precipitation amount and the number of precipitation days in winter) and the retention of captured resources is a higher priority appearing in a low SLA leaves. However, more evidence from a broader study of the species throughout its distribution range by including additional environmental factors and molecular markers are needed for firmer conclusions of intraspecific variability of Rh. caucasicum.

C60 embedded diamond-like nanocomposite thin film

Jana Sukhendu,Das Sayan,De Debasish,Shakti Nanda,Mondal Anup,Bhattacharya Sekhar,Gongopadhyay Utpal 한국탄소학회 2022 Carbon Letters Vol.32 No.1

Diamond-like nanocomposite (DLN) has become a promising thin film for many fields of applications due to its unique and tunable properties. However, low optical bandgap and thermal stability limits its application in many fields particularly as antireflection coating on solar cell. In the present study, the DLN thin film has been deposited using a mixed liquid precursor by rf-PECVD process. Surprisingly the presence of nc-C60 in FCC structure in DLN matrix has been observed. The degree of crystallinity and diameter of C60 have been increased significantly after annealed at 850 °C. The film has been annealed at 850 °C to primarily investigate its feasibility as antireflection coating (ARC) in compatible with industrial solar cell fabrication process. The refractive index and optical bandgap of the film were around 1.80 and 4.10 eV, respectively. Moreover, the optical bandgap has decreased to some extent to 3.92 eV even after annealing at such high temperature. The high SiOx at% and embedded nc-C60 enhanced the optical transparency and thermal stability of the DLN film. The solar-weighted average reflection of DLN-coated textured silicon was reduced significantly to 1.91%. The C60 embedded DLN film has a great potential to apply in different optoelectronic devices especially in solar cell as ARC.

Growth of Ni–Co binary hydroxide on a reduced graphene oxide surface by a successive ionic layer adsorption and reaction (SILAR) method for high performance asymmetric supercapacitor electrodes

Jana, Milan,Saha, Sanjit,Samanta, Pranab,Murmu, Naresh Chandra,Kim, Nam Hoon,Kuila, Tapas,Lee, Joong Hee The Royal Society of Chemistry 2016 Journal of Materials Chemistry A Vol.4 No.6

<▼1><P>Ni–Co–BH–G was prepared by using a SILAR technique and the corresponding asymmetric supercapacitor showed an energy density of 92 W h kg<SUP>−1</SUP>.</P></▼1><▼2><P>A simple, additive-free, cost-effective and scalable successive ionic layer adsorption and reaction (SILAR) method is reported to prepare nickel–cobalt binary hydroxide (Ni–Co–BH) on a reduced graphene oxide (RGO) directing template over a macro-porous conductive nickel foam substrate. This green technique is not only considered as fundamental research interest, but also describes the commercial applications of supercapacitors to reduce the electrode fabrication cost. Three different Ni–Co–BH–G (Ni–Co–BH/RGO) composites are synthesised by tailoring the nickel–cobalt ratios. The flower-like 3D framework of Ni–Co–BH–G provides a porous nano-structure to facilitate the charge transfer and ion diffusion. The cathodic peak current density <I>vs.</I> square root of the scan rate slope values of cyclic voltammetry are consistent with specific capacitance (SC) retention (<I>vs.</I> current density) from charge–discharge curves and the diffusion time constant of the Nyquist plot of the Ni–Co–BH–G composites. Taking the advantage of 3D conductive mesoporous open framework, the Ni–Co–BH–G has provided an excellent SC of 2130 F g<SUP>−1</SUP> at 2 A g<SUP>−1</SUP>. An asymmetric supercapacitor device is designed with the optimized Ni–Co–BH–G as the positive electrode and concentrated HNO3 treated conducting carbon cloth (CCN) as the negative electrode. An excellent energy density of ∼92 W h kg<SUP>−1</SUP> and a high power density of ∼7.0 kW kg<SUP>−1</SUP> with lifetime stability up to 10 000 charge–discharge cycles (capacitance retention ∼ 80%) are provided by the asymmetric device. Four asymmetric devices have been assembled in series, which provided ∼5.6 V charge–discharge potential. The assembled system has powered a 5 V light-emitting diode (LED) successfully.</P></▼2>

Phase- and interlayer spacing-controlled cobalt hydroxides for high performance asymmetric supercapacitor applications

Jana, Milan,Sivakumar, Periyasamy,Kota, Manikantan,Jung, Min Gyu,Park, Ho Seok Elsevier 2019 Journal of Power Sources Vol.422 No.-

<P><B>Abstract</B></P> <P>A facile and selective hydrothermal synthesis is performed to control the crystalline phases of cobalt hydroxides into α-Co(OH)<SUB>2</SUB> and β-Co(OH)<SUB>2</SUB>: α-Co(OH)<SUB>2</SUB>, consisting of both octahedral and tetrahedral Co sites, is produced without ionic liquids, whereas β-Co(OH)<SUB>2</SUB>, containing octahedral Co sites, is synthesized in the presence of ionic liquids. The ionic liquids play significant role as co-solvent and template to tune the morphology of Co(OH)<SUB>2</SUB>. α-Co(OH)<SUB>2</SUB> reveals flake-like structure, whereas β-Co(OH)<SUB>2</SUB> exhibits nanorod-like network structure. The interlayer spacing of α-Co(OH)<SUB>2</SUB> is 8.24 Å, which is larger than 4.63 Å of β-Co(OH)<SUB>2</SUB> due to the expansion of interlayer by the precursor Cl<SUP>─</SUP> anions. The presence of Cl<SUP>─</SUP> anions hinders the insertion of hydroxide ion into α-Co(OH)<SUB>2</SUB> interlayers, which shows the specific capacitance of 613 F g<SUP>─1</SUP> less than 1066 F g<SUP>─1</SUP> of β-Co(OH)<SUB>2</SUB> at 2 A g<SUP>─1</SUP>. When the current density increases up to 20 A g<SUP>─1</SUP>, the capacitance retention of β-Co(OH)<SUB>2</SUB> is 80%, greater than 70% of α-Co(OH)<SUB>2</SUB>. Configuring β-Co(OH)<SUB>2</SUB> and reduced graphene oxide as positive and negative electrodes, asymmetric supercapacitor delivers the maximum energy and power densities of 20.05 W h kg<SUP>─1</SUP> and 13.40 kW kg<SUP>─1</SUP> with the capacitance retention of 93% over 10,000 cycles.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Crystalline phases and interlayer distance of Co(OH)<SUB>2</SUB> are controlled. </LI> <LI> α- and β-Co(OH)<SUB>2</SUB> reveal flake-like and nanorod-like structures. </LI> <LI> β-Co(OH)<SUB>2</SUB> shows 1066 F g<SUP>−1</SUP> at 2 A g<SUP>−1</SUP>. </LI> <LI> β-Co(OH)<SUB>2</SUB> reveals 80% of its initial capacitance at 20 A g<SUP>−1</SUP>. </LI> <LI> Asymmetric supercapacitor achieves 20.05 W h kg<SUP>−1</SUP> and 10,000 cycle stability. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

B3S monolayer: prediction of a high-performance anode material for lithium-ion batteries

Jana, Saibal,Thomas, Siby,Lee, Chi Ho,Jun, Byeongsun,Lee, Sang Uck Royal Society of Chemistry 2019 Journal of Materials Chemistry A Vol.7 No.20

<P>To mitigate the ever-growing global temperature rise, renewable energy is needed and use of fossil fuels has to be reduced on an urgent basis. Next-generation renewable energy technology demands electrode materials with suitable structural, electronic, and mechanical properties. Through particle swarm-intelligence and first-principles structure calculations, we have designed a new novel B3S monolayer, which is dynamically, mechanically, and thermally stable and of higher cohesive energy compared to synthesized B2S3 thus ensuring the feasibility of experimental synthesis. As an anode material, the B3S monolayer can be expected to have high performance with high storage capacity (1662 mA h g<SUP>−1</SUP>), low open-circuit voltage (∼0.16 V) and a low lithium diffusion barrier (<I>E</I>a < 0.4 eV). Furthermore, the metallicity of the B3S monolayer is sustained after lithium adsorption, indicating good electrical conductivity and battery operating cycle. Our results clarify that these intriguing properties make B3S monolayer an appealing candidate for anode material in lithium-ion batteries.</P>