bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular Diagnosis of Schistosomiasis in Feces Samples From Napu Valley Community of Poso Regency, Central Sulawesi, Indonesia
Authors: Indang Nur 
Published: July 2020

Schistosomiasis is infection caused by Schistosoma worms. Schistosomiasis in Indonesia caused by a worm of Schistosoma japonicum, which is an endemic disease and it is only found in Central selawesi, in high land of Napu Valley, Lindu, and Bada villages. Prevalence of schistosomiasis during 2001-2010 experienced fluctuation, which the lowest prevalence was in 2003, it was 0.70%, and the highest prevalence was in 2010, it was 5.68%. In 2012, the proportion of schistosomiasis case in Napu was 1.44%. From 15 Sub-districts examined in Napu Highland area, there were 12 sub-districts which had the prevalence above the WHO standard of 1%. Routine inspection was conducted by the Department of Health-Central Sulawesi microscopically based on Kato-Katz method. Target of this study is to find out comparation accuration data resulted from molecular examination by PCR method, compare to the results of microscopic examination based on Kato-Katz method. This research was an observational descriptive research. Molecular examination by PCR method was done using primers sequencing of forward 5’-TCT AAT GCT ATT GGT TTG AGT-3’ and reverse 5’-TTC CTT ATT TTC ACA AGG TGA-3’. The target umplification was DNA of SjR2 gene, at 230 bp band. Preserved feces samples was done using ethanol 96% at Dodolo village, that have been previously examined microscopically using Kato-Katz method. Based on microscopic examination on 70 samples, 19 sample was positive infected by the worm of S japonicum, and 51 sample of them was shown negative result. Upon further investigation molecularly by PCR, there were 40 people positively detected for infection by the worm S. japonicum, which was shown by appearing on the target band of 230 bp, while 30 others samples were declared negatively. Molecular examination data showed two times more likely in detecting schistosomiasis, compared to microscopic examination by the Kato-Katz method. Our data also showed that Molecular examination using PCR method can be used for 70-96% ethanol-preserved facel samples.
Recognition versus Disclosure and Audit Fees and Costs: Evidence from Pension Accounting in Japan
Authors: Kusano Masaki , Sakuma Yoshihiro 
Published: July 2020

ABSTRACT
Statement No. 26, Accounting Standard for Retirement Benefits, requires Japanese firms to recognize previously off-balance sheet pension liabilities on their balance sheets. We explore auditors' responses to recognized versus disclosed pension liabilities in the Japanese audit market. We use a pre-Statement No. 26 versus post-Statement No. 26 setting to analyze whether and how disclosed versus recognized pension information affects audit fees and costs. We show that disclosed pension liabilities are processed similarly to recognized previously off-balance sheet pension liabilities when audit fees are determined. However, we find that associations with audit costs differ between disclosed and recognized pension liabilities. We also find that audit costs' differential relations with disclosed and recognized pension liabilities are particularly pronounced for firms with a large pension plan deficit. Overall, our results suggest that auditors scrutinize recognized amounts more closely than disclosed financial information, thereby increasing the reliability of accounting information.
JEL Classifications: M41; M42; M48.
Decreased Antihyperglycemic Drug Use Driven by High Out-of-Pocket Costs Despite Medicare Coverage Gap Closure
Authors: Gokhale Mugdha , Dusetzina Stacie B. , Pate Virginia , Chun Danielle S. , Buse John B. , Stürmer Til , Gower Emily W. 
Published: July 2020

OBJECTIVE
Using the 2016 Medicare Part D coverage gap as an example, we explored effects of increased out-of-pocket costs on adherence to branded dipeptidyl peptidase 4 inhibitors (DPP-4i) in patients without financial subsidies relative to subsidized patients who do not experience increased spending during the gap. We also explored seasonality of reinitiation, because discontinuers may be more likely to reinitiate in January when benefits reset.

RESEARCH DESIGN AND METHODS
We identified DPP-4i or sulfonylurea initiators, aged ≥66 years, from a 20% sample of 2015–2016 Medicare claims. Difference-in-differences Poisson regression was used to compare adherence before and after entering the coverage gap between nonsubsidized and subsidized patients. Among discontinuers, monthly hazard ratios (HRs) for reinitiation relative to January 2016 were derived with Cox models. As a second control, we repeated analyses using sulfonylureas, generic low-cost alternatives.

RESULTS
In 2016, 8,096 subsidized and 6,173 nonsubsidized DPP-4i initiators entered the coverage gap. For nonsubsidized patients, copayment in the coverage gap was 45% ($227 per DPP-4i prescription), and adherence decreased from 68.4% to 49.0% after gap entry. Accounting for adherence differences in subsidized patients, nonsubsidized patients demonstrated reduced adherence to DPP-4i (difference-in-difference: −16.9%; 95% CI −18.7%, −15.1%) but not sulfonylureas (−1.6%; 95% CI −3.4%, 0.2%). Reinitiation was lowest in the months before January (HR 0.4–0.5) among nonsubsidized DPP-4i patients, demonstrating a strong seasonal pattern.

CONCLUSIONS
Increased out-of-pocket costs negatively affect adherence and reinitiation of branded antihyperglycemic drugs among patients without financial subsidies. Despite closure of the coverage gap, affordability remains a concern given increasing list prices for many drugs on Medicare and the growing use of deductibles and coinsurance by commercial health plans.
Physical and mechanical characterization of dissimilar laser welded joints of AISI 316/Cu/SMA using fiber laser technology
Authors: Chatterjee Suman , Mahapatra Siba Sankar , Arora Kanwer Singh , Behera Ajit 
Published: July 2020

The present study explores an experimental investigation of dissimilar welding of austenitic stainless steel (AISI 316) with nitinol (NiTi) plates by inserting copper (Cu) as an interlayer using a fiber laser system. The presence of copper influences controlling the formation of brittle intermetallic compounds forming compounds of copper with iron, titanium, and nickel. The weldments are examined to understand the physical and mechanical properties of the joints. A micrograph study of welded joints shows a crack-free surface and reveals the nature of solidification in the weld zone. The analysis of pores in the weldment indicates the presence of 1.89%, 2.26%, and 6.32% of pores in the weld zone area of three different weldment samples, 1, 2, and 3, respectively, and the obtained porosity percentage was quite satisfactory. The insertion of copper helps in attaining the welded joints bearing a tensile strength of 219.74 MPa. The failure of the welded joint shows a mixed nature of fracture. This study suggests that the presence of an interlayer during joining of dissimilar materials provides stable, crack-free, and less brittle joints as compared to joining of dissimilar materials without an interlayer.
The author of the article agrees to the retraction of the article effective JULY 12, 2021.
EFEK ANTIINFLAMASI EKSTRAK ETANOL KULIT KACANG TANAH (Arachis hypogaea L.) PADA TIKUS PUTIH JANTAN GALUR WISTAR YANG DIINDUKSI KARAGENIN
Authors: Haryoto Haryoto 
Published: July 2020

Kulit kacang tanah mengandung luteolin yang berpotensi sebagai antiinflamasi secara in vitro dan in vivo. Penelitian ini bertujuan untuk mengetahui efek antiinflamasi ekstrak etanol kulit kacang tanah (Arachis hypogaea L.) pada tikus jantan galur Wistar yang diinduksi karagenin Penelitian menggunakan rancangan acak lengkap pola searah. Dua puluh lima ekor tikus putih jantan galur Wistar dibagi menjadi 5 kelompok. Kontrol negatif menggunakan CMC-Na 0,5% 2,5 mL/200 gBB, kontrol positif menggunakan Na-diklofenak 6,75 mg/kgBB. Ekstrak etanol kulit kacang tanah yang diujikan yaitu dosis 50, 100 dan 200 mg/kgBB. Larutan uji diberikan secara peroral dengan volume pemberian 2,5 mL/200 gBB 1 jam sebelum kaki hewan uji diradangkan dengan karagenin 1% secara subplantar. Pengukuran volume kaki tikus dilakukan tiap 0,5 jam selama 6 jam. Data volume udem dihitung nilai AUC (Area Under the Curve) rata-rata volume udem terhadap waktu dan persen daya antiinflamasi. Data dianalisis dengan anava satu jalan dan dilanjutkan uji LSD (Least Significant Difference) dengan taraf kepercayaan 95%. Hasil penelitian menunjukkan bahwa ekstrak etanol etanol kulit kacang tanah (Arachis hypogae L.) dengan dosis 50, 100 dan 200 mg/kgBB mempunyai persen daya antiinflamasi berturut-turut sebesar 16,33%; 26,39% dan 31,70%, sedangkan Na-diklofenak 6,75 mg/kgBB sebesar 32,24%.Kata kunci: kulit kacang tanah (Arachis hypogaea L.), ekstrak etanol, antiinflamasi
SINTESIS SENYAWA ANALOG KURKUMIN 3,5-BIS-(4’-HIDROKSI-3’-METOKSI BENZILIDIN)-PIPERIDIN 4-ON (MONOHIDRAT HIDROKLORIDA) DENGAN KATALIS HCl
Authors: Da'i Muhammad 
Published: July 2020

Kurkumin merupakan senyawa yang mempunyai aktivitas biologis sebagai antialzheimer, antiinflamasi, antioksidan, antikanker dan anti-HIV. Stabilitas kurkumin dipengaruhi oleh pH lingkungan dan cahaya karena ada gugus metilen aktif pada β-diketon. Oleh karena itu, dibutuhkan modifikasi gugus β-diketon menjadi gugus monoketon untuk menghilangkan gugus metilen aktif sehingga dapat meningkatkan stabilitas dari analog kurkumin. Berdasar analisis tersebut dapat dikembangkan sintesis analog kurkumin 3,5-bis-(4׳-hidroksi-3׳-metoksi-benzilidin)-piperidin-4-on monohidrat hidroklorida dari reaksi kondensasi aldol antara starting material vanilin dan piperidin 4-on monohidrat hidroklorida dengan katalis asam (HCl). Metode sintesis dioptimasi dari perbandingan perubahan suhu dan pH sedangkan analisis senyawa hasil sintesis dilakukan secara kualitatif. Analisis tersebut antara lain, perubahan warna, KLT-densitometri, spektrofotometri UV-Vis, dan LC-ESI-MS. Hasil penelitian menunjukkan pada metode sintesis refluks dengan suhu 80-90 oC, perbandingan mol 2:1 (mmol), dan pH 2 dapat disintesis senyawa analog kurkumin 3,5-bis-(4׳-hidroksi-3׳-metoksi-benzilidin)-piperidin-4-on monohidrat hidroklorida. Identifikasi senyawa tersebut diperoleh dari perubahan warna menjadi orange, hasil KLT terdapat spot baru yang berfluorosensi, hasil spektrofotometri UV-Vis terjadi batochromic shift, dan hasil LC-ESI-MS terdapat ion molekul yang sama dengan BM molekul target. Kata kunci: analog kurkumin 3,5-bis-(4’-hidroksi-3’-metoksi-benzilidin) piperidin 4-on monohidrat hidroklorida, katalis HCl, kondensasi aldol, spektrofometri UV-Vis, LC-ESI-MS
PGV-0 AND PGV-1 INCREASED APOPTOSIS INDUCTION OF DOXORUBICIN ON MCF-7 BREAST CANCER CELLS
Authors: Meiyanto Edy 
Published: July 2020

As chemotherapeutic backbone for breast cancer therapy, doxorubicin showed various side effects and induced resistancy of breast cancer cells. Development of targeted therapy on breast cancer focused on combinatorial therapy of doxorubicin and molecular targeted agents. PGV-0 and PGV-1, a curcumin analogue showed potency as co-chemotherapeutic agent with doxorubicin. Our previous study of PGV-0 and PGV-1 showed cytotoxic activity in T47D cells. Therefore, the aim of this research is to examine the synergistic effect of PGV-0, PGV-1 on the cytotoxic activity of doxorubicin through cell cycle modulation and apoptotic induction on MCF-7 breast cancer cell lines. The cytotoxic assay of PGV-0, PGV-1, doxorubicin, and their combination were carried out by using MTT assay. Cell cycle distribution and apoptosis were determined by flowcytometer FACS-Calibur and the flowcytometry data was analyzed using Cell Quest program. Single treatment of PGV-0, PGV-1 and doxorubicin showed cytotoxic effect on MCF-7 with cell viability IC50 value 50 µM, 6 µM and 350 nM respectively. Single treatment of Doxorubicin 175 nM induced G2/M arrest. Single treatment of PGV-0 5 µM induced G2/M arrest while in higher dose 12.5 µM, PGV-0 induced apoptosis. Combination of doxorubicin 175 nM and PGV-0 5 µM induced apoptosis. Combination of doxorubicin 175 nM and PGV-0 12.5 µM also increased apoptosis induction. Single treatment of PGV-1 0.6 µM induced G1 arrest while in higher dose 1.5 µM, PGV-1 induced apoptosis. Combination of doxorubicin 175 nM and PGV-1 0.6 µM induced apoptosis. Combination of doxorubicin 175 nM and PGV-0 1.5 µM also increased apoptosis induction. PGV-0 and PGV-1 are potential to be delevoped as co-chemotherapeutic agent for breast cancer by inducing apoptosis and cell cycle modulation, but the molecular mechanism need to be explored detail. Key words: PGV-0, PGV-1, doxorubicin, co-chemotherapy, breast cancer, cell cycle arrest, apoptosis
EKSTRAK ETANOLIK DAUN Gynura procumbens (Luor) Merr. MENGHAMBAT PROLIFERASI SEL KANKER PAYUDARA TIKUS PADA KARSINOGENESIS YANG DIINDUKSI DENGAN dimetilbenz(a)antrazena (DMBA)
Authors: Meiyanto Edy 
Published: July 2020

Penelitian sebelumnya menunjukkan bahwa ekstrak etanolik daun Gynura procumbens dapat menghambat pertumbuhan tumor payudara tikus yang diinduksi DMBA. Penelitian ini bertujuan untuk mengetahui efek ekstrak etanolik daun Sambung nyawa (Gynura procumbens (Luor) Merr) pada proliferasi sel kanker payudara tikus yang diinduksi dengan Dimetilbenz(a)antrazena (DMBA). Enam puluh ekor tikus betina galur SD umur 6 minggu dibagi menjadi 6 kelompok yaitu tanpa perlakuan, perlakuan DMBA saja dan empat kelompok perlakuan DMBA+ekstrak. Inisiasi DMBA dilakukan dengan dosis 20 mg/kgBB yang diberikan sebanyak 10 kali dengan frekuensi pemberian 2 kali setiap minggu. Mulai minggu ke-1 (post I) atau ke-6 (post II) kelompok perlakuan mendapat ekstrak etanolik daun Gynura procumbens dalam CMC 0,5 % seminggu 3 kali melalui oral dengan dosis 250 mg/kgBB dan 750 mg/kgBB. Pada minggu ke-16 tikus dikorbankan, jaringan payudara diambil untuk dibuat preparat histologi dengan teknik pewarnaan silver (AgNOR). Mean AgNOR (mAgNOR) dihitung pada setiap preparat tiap kelompok. mAgNOR kelompok perlakuan dibandingkan dengan mAgNOR kelompok tanpa perlakuan. Hasil penelitian menunjukkan ekstrak etanolik daun Gynura procumbens dengan dosis 250 mg/kgBB dan 750 mg/kgBB yang diberikan mulai minggu kesatu maupun ke-6 setelah inisiasi DMBA terakhir dapat mengurangi proliferasi sel kanker payudara tikus. Rata-rata mAgNOR kelompok tanpa perlakuan dan perlakuan DMBA saja masing-masing 0,8 ± 0,34 dan 2,7 ± 0,41, mAgNOR post I kelompok dosis 250 dan dosis 750 masing-masing 1,4 ± 0,39 dan 1,3 ± 0,09, sedangkan mAgNOR post II kelompok dosis 250 dan dosis 750 masing-masing 1,6 ± 0,47 dan 1,5 ± 0,31. Pengamatan terhadap ekspresi COX-2 menunjukkan adanya penurunan pada kelompok perlakuan ekstrak dosis 250 dan 750 mg/kgBB. Hasil-hasil tersebut menunjukkan bahwa ekstrak etanolik daun Gynura procumbens dapat menghambat proliferasi sel-sel tumor payudara yang kemungkinan berhubungan dengan penurunan ekspresi COX-2. Kata kunci: Gynura procumbens, anti-karsinogenesis, proliferasi, AgNOR
3D-MOLECULAR SCREENING OF DIKETOPIPERAZINE DERIVATES ON Staphylococcus aureus DEHYDROSQUALENE SYNTHASE USING VINA
Authors: Santoso Broto 
Published: July 2020

Dehydrosqualene synthase enzyme has been used as protein target model for exploring docking simulation of pyrazoline analogues. One of diketopiperazine derivates that have similar structure to pyrazoline has antibacterial activity against Staphylococcus aureus (S. aureus). Vina is AutoDock- improved program that capable for molecular screening based on free-energy and binding conformation prediction between ligand and protein target. The aim of these studies is to screen diketopiperazine derivates on dehydrosqualene synthase of S. aureus using Vina. Diketopiperazine derivates, curcumin analogues, curcumin, pentagammavunon derivates (PGV-0 and PGV-1) were calculated for their geometry optimization energy using Gaussian-Density Functional Theory method. 3D-optimized ligands along with reference ligands were screened for their binding energy with dehydrosqualene synthase (2ZCO) by docking using Vina. The lowest values of binding energy were analyzed with statistic method. The results showed that top thirteen ligands of docking binding energy with receptor are diketopiperazine derivates (31%), curcumin analogues (31%), and reference ligands (38%). The new compounds of diketopiperazine derivates and curcumin analogues have better potency of binding energy than curcurmin as lead compound. Keywords: diketopiperazine, Vina, docking, Staphylococcus aureus, curcumin.
EFEK INFUSA BUNGA ROSELLA (Hibiscus sabdariffa) PADA SERUM GLUTAMATE PIRUVAT TRANSAMINASE TIKUS YANG DIINDUKSI PARASETAMOL DOSIS TOKSIK
Authors: Sudjono Tanti Azizah 
Published: July 2020

Kadar Serum Glutamat Piruvat Transaminase (SGPT) bisa meningkat dibandingkan normalnya pada gangguan fungsi hati seperti nekrosis sel hati yang disebabkan oleh virus atau hepatotoksin seperti parasetamol pada dosis toksik. Penelitian ini bertujuan untuk mengetahui efek infusa bunga rosella (Hibiscus sabdariffa) terhadap penurunan kadar SGPT tikus yang diinduksi parasetamol. Penelitian ini menggunakan 25 tikus jantan, umur 2-3 bulan yang dibagi secara acak menjadi 5 kelompok. Kelompok I sebagai kontrol normal diberi aquadest, kelompok II sebagai kontrol negatif diberi aquadest, kelompok III sampai V diberi infusa bunga rosella konsentrasi 10, 20 dan 40%. Untuk kelompok II sampai V, masing-masing perlakuan diberikan selama 7 hari berturut-turut dan pada jam ke-24 setelah perlakuan hari yang terakhir diinduksi parasetamol dosis toksik, selanjutnya pada jam ke-36 diambil darah dari vena lateralis ekor untuk penetapan kadar SGPT. Hasil penelitian menunjukkan bahwa infusa bunga rosella konsentrasi 20% dan 40% pada pemberian dosis berulang selama 7 hari mampu menurunkan kadar SGPT pada tikus jantan galur Wistar yang diinduksi parasetamol (p0,05), dengan kadar SGPT berturut-turut menjadi 388,8±18,79 dan 172,2±87,48 U/L, sedangkan kontrol negatif 1190±443 U/L. Kata kunci : Hibiscus sabdariffa, SGPT, parasetamolcolor:text1'.forma citratum Back., Graptophylum pictum Griff, Gynura procumbens Merr.
UJI AKTIVITAS ANTIRADIKAL EKSTRAK ETANOL DAUN Elephantopus schaber L., Ocimum basilicum L.forma citratum Back., Graptophylum pictum Griff, dan Gynura procumbens Merr. DENGAN METODE DPPH (1,1- Difenil-2- Pikril Hidrazil) SERTA PENETAPAN KADAR FENOLIK TOT
Authors: Da'i Muhammad , Ratnaningrum Astrina Dewi , Wahyuni Arifah Sri , Melannisa Rosita , Dian Kusuma Ika Trisharyanti 
Published: July 2020

Daun Elephantopus schaber L. (tapak liman), Ocimum basilicum L.forma citratum Back., (selasih) Graptophylum pictum Griff (daun ungu), dan Gynura procumbens Merr. (sambung nyawa) memiliki kandungan kimia yang dapat berperan sebagai antiradikal, diantaranya adalah senyawa fenolik. Penelitian ini dilakukan untuk melihat korelasi kandungan fenolik total keempat daun terhadap aktivitas antiradikalnya. Sampel uji yaitu ekstrak etanol daun selasih, ungu, sambung nyawa, dan tapak liman ditentukan aktivitas antiradikal dengan menggunakan metode DPPH (1,1 difenil-2-pikrilhidrazil) kemudian dihitung nilai inhibitory concentration (IC50). Kandungan fenolik total ditentukan secara spektrofotometri menggunakan pereaksi Folin-Ciocalteu dan dihitung sebagai GAE (gallic acid equivalent) yaitu jumlah kesetaraan miligram asam galat dalam satu gram sampel. Penelitian menunjukkan ekstrak etanol daun selasih, ungu, sambung nyawa dan tapak liman memiliki aktivitas antiradikal dengan nilai IC50 berturut-turut 36,028; 54,998; 103,650; 252,857µg/mL dan kadar fenolik total berturut-turut 167,451; 147,064; 39,371 dan 20,539 mg/g sampel. Hasil penelitian secara keseluruhan menunjukkan ekstrak etanol daun selasih, ungu, sambung nyawa dan tapak liman berkorelasi positif terhadap aktivitas antiradikalnya. Kata kunci: Antiradikal, DPPH, IC50, fenolik total, Elephantopus schaber L., Ocimum basilicum L.forma citratum Back., Graptophylum pictum Griff, Gynura procumbens Merr.
Sosialisasi Program Latihan Motor Ablity Kepada Asisten Pelatih Dojo Lembaga Karate-Do Indonesia Se-Kecamatan Koto Tangah
Authors: Asnaldi Arie , Kibadra Kibadra 
Published: July 2020

The role of a Dojo trainer in directing karateka to be able to achieve the things mentioned above, the City of Padang has many Dojo including the Dojo Angkasa Lanud Padang. Dojo in the general sense is a training ground. According to Wahid (2007: 8) Dojo which means "a place to study" in Japanese in the past refers to the meaning of "hall to meditate in the temple".
Padang Dojo Angkasa Lanud is one of the Dojo Lemkari (Indonesian Karate-DO Institute) which has a Karate shutdown in Padang City, the karateka dojo consists of students from Angkasa Lanud Padang Middle School and the general public. Karateka at the Lemkari Angkasa Lanud Dojo Padang has a variety of achievements where in the past it had had quite a proud achievement that karateka performed in the Kata and kumite categories.
UPAYA MENINGKATKAN PEMBELAJARAN KETERAMPILAN BOLAVOLI MELALUI PENDEKATAN SAINTIFIK BERBASIS PENILAIAN AUTENTIK
Authors: Can Ernawati 
Published: July 2020

Berdasarkanpengamatanpenulis di SMP Negeri 2 Pekanbarupembeljaran PJOK padamateri bola volikurangmenarik.Tidakmenariknyapembelajaran PJOK terutamapadamateribolavoliperluditinjauulang, karenahasilbelajarsiswabelumbisadikatakankegagalandalam proses pembelajaran yang dilakukan. Penelitianinibertujuanuntukmelihatimplementasipendekatansaintifikdengan proses penilaianautentikpadapembelajaranbolavoli di SMP Negeri 2 Pekanbaru.
Metodepenelitianiniyaitupenelitiantindakankelas (PTK) yang merupakansuatupencermatanterhadapkegiatanbelajar, Sebagaisubjekpenelitianiniadalahkelas VIII. 3, tahunpelajaran 2014/2015 denganjumlahsiswasebanyak 36 orang, terdiridari 15 laki-lakidan 21 perempuan. Adapunlangkah-langkahpelaksanaan PTK secaraprosedurnyaadalahdilaksanakansecarapasrtisipatifdandilanjutkandenganpenyusunanrencanatindakan, danpelaksanaantindakandalamsiklus.
Berdasarkanhasilpenelitian yang dilakukanTerdapatpeningkatanketerampilan bola volimelaluipembelajarandenganpendekatansaintifikdengapenilaianautentikpadapelajar SMP Negeri 2 Pekanbaru Riau. Hal initerbuktidarihasiltindakansikluspertama yang termasukkategorirendahartinyasebagaipelajar yang mampumelakukanteknikdasarketerampilan bola voli. Sedangkanpadasiklusketigaketerampilanberadapadakategoritinggi, yang berartijikadilihatdarijumlahpelajarkeseluruhanpeningkatanketerampilan bola volisudahterlihat. Terdapatpeningkatan yang sangatberartidalamperkembanganteknikdasar bola volidenganpembelajaranpendekatansaintifik.
KONTRAKSI OTOT SKELET
Authors: M Madri 
Published: July 2020

Secara mekanisme kontraksi otot adalah terjadinya sliding filamen, sedangkan rangkaian proses kontraksi secara sederhana merupakan (1) adanya rangsangan dari otak melalui akson neuron motorik keserabut otot, (2) asetilkolin yang berada disynaptic gutter akan berikatan dengan reseptornyapada sarkolema, sehingga terjadi depolarisasi membran dan menimbulkan potensial aksi sel otot rangkaserta menyebabkan ion natrium dan kalium keluar, dan (3) potensial aksi yang disebarkan dari membran sel akan diteruskan melalui tubulus T, selanjutnya merangsang terminal sisterna sarkoplasmik retikulumuntuk melepaskan ion kalsium. Ion kalsium akan berikatan dengan troponin Cpada filamen aktin dan mendorong filamen tropomiosin menutup celah-celah aktivesite filamen aktin, sehingga aktivesite terbuka.
Otot merupakan jaringan peka yang dapat dirangsang untuk menimbulkan suatu potensial aksi. Otot rangka melekat pada tulang dan berperan sebagai sistem perototan yang menggerakan tubuh. Aktivitas otot diatur oleh susunan saraf melalui persarafan motorik. Otot rangka tersusun dari serat-serat yang merupakan balok penyusun (building bloks) sistem otot. 40% dari berat badan manusia terdiri dari otot rangka dan 10% terdiri dari otot polos dan jantung. Mekanisme kontraktil ototrangka tergantung dari protein miosin, aktin, troponin dan tropomiosin. Ciri filamen miosin tebal, sedangkan filamen aktin tipis. Sebagian saling bertautan sehingga menyebabkan myofibril secara bergantian menunjukan pita terang dan gelap. Pita ini saling tumpang tindih dan terjadi penonjolan dari sisi filamen miosin. Penonjolan ini dinamakan jembatanpenyeberangan (cross bridge).