Penerapan Strategi Pembelajaran Inkuiri Dipadukan Media Audio Visual Untuk Meningkatkan Kualitas Pembelajaran Biologi Siswa Kelas VII D SMP N 1 Jaten

– The aim of this research is improve quality of biology learning for conditioning class, student attitude in class, the performance of teacher and student motivation of learning in student class VII-D 1st Junior High School Of Jaten through the application of strategies for inquiry learning combined audio visual media. This research was classroom action research with planning, action, observation, and reflection steps. Data was collected using questionnaire, observation, and interview. The validation of data using method and observer triangulation techniques. The data analyzed by descriptive. The result in cycles I describes that mean of observation data in conditioning class indicators are 70,20%, students\u27 attitudes in class are 62,77%, performance of teachers in the learning are 80% and students motivation in learning are 68,18%. For the questionnaire, observation data in conditioning class indicators are 74,53%, students\u27 attitudes in class are 74,13%, and students motivation in learning are 74,38%. The result in cycles II describes that mean of observation data in conditioning class indicators are 80,81%, students\u27 attitudes in class are 80.09%, performance of teachers in the learning are 96,67% and student motivation in learning are 83,71%. For the questionnaire, observation data in conditioning class indicators are 83,87%, students\u27 attitudes in class are 82,49%, and students motivation in learning are 79,43%. In addition, this research also uses interview to know effect of research in quality of biology learning. The result of interview shows that students\u27 attitudes more positive, students motivation more increase and classroom climate more conducive on learning activities. The conclusion of research describes that the combination of audio visual media in inquiry learning strategies can improve quality of biology learning for conditioning class, students\u27 attitudes, performance of teachers in the learning and motivation of learning in student class VII-D in 1st junior high school of jaten

On the Lab. II building site

425 special CDSs in PCN033 (XLSX 29 kb

Fast and Controlled Ring-Opening Polymerization of Cyclic Esters by Alkoxides and Cyclic Amides

Ring-opening polymerization is a powerful method for the synthesis of biodegradable and biorenewable polyesters. In this contribution, we report that the combination of alkali alkoxides and commercially available cyclic amides catalyzes fast and controlled ring-opening polymerization of l-lactide. The constrained cis CN bond in the imidate catalyst is critical for achieving high catalytic activity. By optimizing the basicity of the catalyst, a good balance between activity and control (<i>M</i>_w/<i>M</i>_n < 1.1) is realized. A high amide/initiator ratio is essential for producing narrow dispersities and inhibiting transesterification

Ag₂O/TiO₂ Nanocomposite Heterostructure as a Dual Functional Semiconducting Substrate for SERS/SEIRAS Application

Surface-enhanced Raman spectroscopy (SERS) and surface-enhanced infrared absorption spectroscopy (SEIRAS) are complementary and powerful techniques for molecular characterization and detection. However, studies on substrates that can enhance both Raman and IR singles are extremely scanty. Here, we reported a hybrid semiconductor material (Ag₂O/TiO₂) coupled with a portable solid support served as a dual functional platform for both SERS and SEIRAS applications. A facile two-step deposition method was used to synthesize Ag₂O/TiO₂ nanocomposite on a flexible polymeric membrane without bringing any external chemical capping agent and background signal. The presence of Ag₂O was proposed to enrich the photogenerated electrons onto TiO₂ surface and facilitate the photon-induced charge transfer (PICT) between TiO₂ and adsorbate. The heterostructure of Ag₂O/TiO₂ could bring additional enhancement. The enhancement factor from such hybrid semiconducting substrate was at least one or two orders of magnitude over traditional semiconducting materials and comparable to noble metals. Additionally, this substrate enabled the ultratrace detection regardless of the more Raman- or IR-active molecules and displayed distinct quantitative capacities for SERS and SEIRAS. High reproducibility of the SERS/SEIRAS spectra further confirmed the reliability and reproducibility of our substrates

Rapid detection of TiO₂ (E171) in table sugar using Raman spectroscopy

<p>The potential toxic effects of titanium dioxide (TiO₂) to humans remain debatable despite its broad application as a food additive. Thus, confirmation of the existence of TiO₂ particles in food matrices and subsequently quantifying them are becoming increasingly critical. This study developed a facile, rapid (< 30 min) and highly reliable method to detect and quantify TiO₂ particles (E171) from food products (e.g., table sugar) by Raman spectroscopy. To detect TiO₂ particles from sugar solution, sequential centrifugation and washing procedures were effectively applied to separate and recover 97% of TiO₂ particles from the sugar solution. The peak intensity of TiO₂ sensitively responded to the concentration of TiO₂ with a limit of detection (LOD) of 0.073 mg kg^–1. In the case of sugar granules, a mapping technique was applied to directly estimate the level of TiO₂, which can be potentially used for rapid online monitoring. The plot of averaged intensity to TiO₂ concentration in the sugar granules exhibited a good linear relationship in the wide range of 5–2000 mg kg^–1, with an LOD of 8.46 mg kg^–1. Additionally, we applied Raman spectroscopy to prove the presence of TiO₂ in sugar-coated doughnuts. This study begins to fill in the analytical gaps that exist regarding the rapid detection and quantification of TiO₂ in food, which facilitate the risk assessment of TiO₂ through food exposure.</p

Three-Component Reaction from But-2-Ynedioate, Triphenylphosphine, and Substituted Chalcones: to Access Highly Substituted (Triphenylphosphoranylidene) Cyclopentadienecarboxylates

<div><p>GRAPHICAL ABSTRACT</p><p></p></div

Raw data

The raw data file contains files relevant to data extraction, data analysis and other data relevant with contents in supplementary file

Pd(II)/Lewis Acid Catalyzed Intramolecular Annulation of Indolecarboxamides with Dioxygen through Dual C–H Activation

Transition-metal ion catalyzed intramolecular dual C–H activation to construct polycyclic heteroarene skeletons is merited for its step and atom-economic advantages in organic synthesis. However, in most cases, stoichiometric oxidants, elevated temperature, and other harsh conditions were commonly faced for this reaction, which apparently block the synthetic applications. Herein, we report a Pd(II)/LA (LA: Lewis acid) catalyzed intramolecular dual C–H activation to construct indoloquinolinone derivatives under mild conditions with dioxygen as the sole oxidant. It was found that adding LA such as Sc3+ to Pd(OAc)2 sharply improved its catalytic efficiency, whereas Pd(OAc)2 alone was very sluggish. The activity improvement was attributed to the linkage of the Sc3+ cation to the Pd(II) species through a diacetate bridge that significantly enhanced the electrophilic properties of Pd(II) for dual C–H activation

Observing the Agostic Hydrogen in Pd(II)-Catalyzed Aromatic C–H Activation

Direct C–H activation and functionalization offer a convenient protocol for pharmaceutical and material syntheses. Although versatile mechanisms have been proposed to depict transition-metal-catalyzed C–H activation, to date, the shared key agostic hydrogen intermediate in several major mechanisms has not been observed yet, which apparently puzzles the mechanism-based catalyst design. This work reports the direct observations of this intermediate in Pd(II)/Sc(III)-catalyzed C–H activation of acetanilides, and its stability and reactivity in C–H activation are investigated. Remarkably, this intermediate is only observed in electron-rich acetanilides, and the meta-substituent with increased σm constant generally accelerates C–H activation, a characteristic of the base-assisted C–H activation mechanism. This study has unveiled the masks of this intermediate with an understanding of its first-hand physicochemical properties, shedding new light on mechanism-based catalyst design

Fabrication of Epigallocatechin-3-gallate Nanocarrier Based on Glycosylated Casein: Stability and Interaction Mechanism

Polyphenols normally have strong binding affinity with proteins, which may lead to protein precipitation. Glycosylation of protein via Maillard reaction in mild condition may inhibit the precipitation. This study prepared nanocomplexes of epigallocatechin-3-gallate (EGCG) and protein, and their stability against environmental stress was investigated. Subsequently, these findings were correlated with the interactions between EGCG and casein. Results showed that glycosylated casein displayed strong encapsulating and retaining capacity to EGCG, and no obvious aggregation or fusion appeared in the concentration range of 0.25–5.00 mg/mL during storage. The in vitro release demonstrated that casein, especially glycosylated casein, could effectively protect EGCG from degradation in alkaline pH and displayed a slow and sustained release in intestinal fluid, which may be attributed to the inhibiting effects of casein binding on the motion freedom of EGCG. Fluorescence quenching spectra demonstrated that the steric hindrance induced by dextran could inhibit the interaction between casein and EGCG. These findings demonstrated that glycosylated casein could be used as a promising and effective nanocarrier for EGCG