Hasil Pencarian  ::  Simpan CSV :: Kembali

"Wild mud crabs of the genus, Scylla paramamosain were acclimatized in tanks in the AKUATROP hatchery. eye stalk ablation was applied on the mud crabs before transferring them into a recirculating aquaculture system, where they were fed marine fish, squid and cockles for a period of one month until they produced eggs. The larvae which hatched out were placed in different larval tanks with continuous aeration. Larvae were fed daily with artemia. the density of larvae culture was 100-300 individuals per liter. the peritrich ciliates found on megalopa larva of mud crabs, Scylla paramamosain were Zoothamnium alrashedi and Myoschiston duplicatum and an unidentified peritrich ciliate. Mangrove leaf extract of Rhizophora apiculata showed that it is capable of being an anti- protozoan product as the zooids of the peritrich ciliates dropped off after treatment with the extract. the breeding tanks were kept clean, probiotics was introduced with plenty of aeration. green water system was activated to ensure plenty of natural food namely rotifers to ensure moulting of megalopa larva into crablet larva."

"Pada penelitian ini, nanopartikel NiCo₂O₄ telah berhasil dipreparasi menggunakan metode green synthesis dengan memanfaatkan metabolit sekunder dalam ekstrak daun cocor bebek (Bryophyllum pinnatum) sebagai sumber basa lemah dan capping agent dalam pembentukan nanopartikel. Ekstrak daun cocor bebek (Bryophyllum pinnatum) dari hasil uji fitokimia diketahui mengandung metabolit sekunder antara lain alkaloid, flavonoid, saponin, dan terpenoid. Dengan %rendemen dan %konsentrasi ekstrak masing-masing sebesar 1,71% dan 0,55%.  Karakterisasi FTIR, XRD, SEM dan TEM digunakan untuk mengkarakterisasi nanopartikel hasil sintesis. Karakterisasi FTIR menunjukkan bahwa nanopartikel NiCo₂O₄ menghasilkan puncak serapan pada bilangan gelombang 569 cm^-1 dan 655 cm^-1 yang disebabkan vibrasi stretching Ni-O dan vibrasi stretching Co-O. Karakterisasi XRD menunjukkan bahwa nanopartikel NiCo₂O₄ hasil sintesis memiliki struktur spinel kubik. Hasil karakterisasi SEM dan TEM diketahui nanopartikel NiCo₂O₄ memiliki morfologi spherical dengan ukuran rata-rata sebesar 25,84 nm. Aktivitas katalitis nanopartikel NiCo₂O₄ terhadap reduksi 2,4,6-trinitrofenol menghasilkan persentase reduksi sebesar 80,46% dengan mengikuti kinetika hukum laju reaksi pseudo orde satu.

---

In this study, NiCo₂O₄ nanoparticle were succesfully preparated with green synthesis method using Bryophyllum pinnatum leaf extract as weak base source and capping agent for the growth nanoparticle. Bryophyllum pinnatum leaf extract from phytochemicals test are known to contain alkaloids, flavonoids, saponins, and terpenoids. With %yield and %concentration extract is 1,71% and 0,55% respectively. FTIR, XRD, SEM and TEM were used to characterize the synthesized nanoparticle. The characterization of FTIR showed that NiCo₂O₄ nanoparticles showed peaks at wave numbers 569 cm^-1 and 655 cm^-1 caused by stretching of Ni-O and stretching of Co-O respectively. The characterization of XRD showed that the synthesized NiCo₂O₄ nanoparticles has a cubic spinel structure. The SEM and TEM characterization revealed that NiCo₂O₄ nanoparticles has spherical morphology with an average size of 25.84 nm. The catalytic activity of NiCo₂O₄ nanoparticles for reduction of 2,4,6-trinitrophenols with a persentage reduction of 80.46% in 50 minutes and the reaction follows pseudo first order kinetics."

"Pada penelitian ini, sintesis nanopartikel ZnO, nanopartikel Ce2Sn2O7, dan nanokomposit ZnO/Ce2Sn2O7 berhasil dilakukan dengan metode green synthesis menggunakan ekstrak daun kirinyuh (Chromolaena odorata L.). Kandungan metabolit sekunder pada daun kirinyuh seperti alkaloid dan saponin dimanfaatkan sebagai basa lemah dan capping agent dalam proses sintesis. Karakterisasi FTIR, XRD, UV-Vis DRS, dan FESEM-EDX dilakukan untuk mengetahui sifat struktural, optik, maupun morfologi dari nanopartikel dan nanokomposit yang dihasilkan. Berdasarkan hasil karakterisasi menggunakan UV-Vis DRS, diperoleh nilai energi band gap dari nanopartikel ZnO, nanopartikel Ce2Sn2O7, dan nanokomposit ZnO/Ce2Sn2O7 masing-masing sebesar 3,00 eV; 2,41 eV; dan 2,52 eV. Selain itu, hasil uji fotokatalitik menunjukkan bahwa nanokomposit ZnO/Ce2Sn2O7 memiliki aktivitas fotokatalitik yang paling baik dibandingkan nanopartikel ZnO dan Ce2Sn2O7 dalam mendegradasi rifampicin di bawah sinar tampak selama 120 menit. Persen fotodegradasi rifampicin oleh ZnO/Ce2Sn2O7, Ce2Sn2O7, dan ZnO berturut-turut sebesar 92,25%; 68,57%; dan 55,38%. Lebih lanjut, reaksi fotodegradasi rifampicin menggunakan ZnO/Ce2Sn2O7 mengikuti kinetika laju pseudo orde satu.

---

In this research, synthesis of ZnO nanoparticles, Ce2Sn2O7 nanoparticles, and ZnO/Ce2Sn2O7 nanocomposites were successfully carried out by means of green synthesis method using siam weed (Chromolaena odorata L.) leaf extract. The secondary metabolites in siam weed leaf such as alkaloids and saponins were used as weak bases and capping agents in the synthesis process. FTIR, XRD, UV-Vis DRS, and FESEM-EDX measurements were conducted to elucidate the structural, optical, and morphological properties of nanoparticles and nanocomposites. Based on the results of characterization using UV-Vis DRS, the band gap energy values ​​of ZnO nanoparticles, Ce2Sn2O7 nanoparticles, and ZnO/Ce2Sn2O7 nanocomposites were 3.00 eV, 2.41 eV, and 2.52 eV. In addition, the photocatalytic test results showed that ZnO/Ce2Sn2O7 nanocomposites had the best photocatalytic activity compared to ZnO and Ce2Sn2O7 nanoparticles against rifampicin under visible light for 120 minutes. Rifampicin photodegradation percentage by ZnO/Ce2Sn2O7, Ce2Sn2O7, and ZnO obtained were 92.25%, 68.57%, dan 55.38%, respectively. Additionally, the reaction kinetics of rifampicin photodegradation using ZnO/Ce2Sn2O7 was found to be a pseudo-first-order rate."

"Karbon adalah atom yang diubah menjadi material yang sangat berlimpah di dunia. Karbon dapat digunakan menjadi material yang sangat berguna yaitu material pelapis yang digunakan untuk membangun bangunan, material komposit, material pengantar listrik, material penyerap (adsorben), dan lain-lain. Grafit adalah material yang mengandung alotrop karbon. Grafit merupakan material yang sangat berlimpah di dunia. Oleh karena itu, grafit dapat diolah menjadi material yang dipakai pada setiap saat. Oksida grafit memiliki struktur berlapis yang mirip dengan stuktur grafit. Hasil XRD menunjukkan bahwa lapisan grafit yang memiliki lapisan 109 lapisan dikupas menjadi 2 sampai 4 lapisan. Jika lembaran terkelupas yang mengakibatkan karbon hanya mengandung satu lapisan atau beberapa lapisan maka lembaran ini diberi nama menjadi grafena oksida (GO). GO dibuat melalui proses Hummers termodifikasi. GO mudah diproses menjadi grafena oksida tereduksi (rGO). Grafena oksida direduksi oleh glisina, asam askorbat, dan ekstrak lemon sebagai pereduksi hijau. Variasi penelitian grafena oksida tereduksi adalah massa grafena oksida dengan massa pereduksi. Hasil karakterisasi grafena oksida tereduksi adalah hasil ftir grafena oksida tereduksi tidak curam pada berkisar gelombang 3100 sampai 3500 cm-1 yang menunjukkan bahwa ikatan -OH, gelombang 1500-1600 cm-1 yang menunjukkan bahwa ikatan C=C, dan gelombang 1000 sampai 1300 cm-1 yang menunjukkan bahwa ikatan C-O; konsentrasi pereduksi hijau mempengaruhi unsur C yang dikandung di dalam rGO berkisar antara 82,81 sampai 85,33% dan unsur O yang dikandung di dalam rGO berkisar antara 8,60 sampai 14,85%.

---

Carbon is an atom that is transformed into the most abundant material in the world. Carbon can be used as a very useful material, namely coating materials used to build buildings, composite materials, electrical delivery materials, absorbent materials, and others. Graphite is a material that contains allotropes of carbon. Graphite is the most abundant material in the world. Therefore, graphite can be processed into materials that are used at any time. Graphite oxide has a layered structure similar to that of graphite. XRD results show that the graphite layer which has a layer of 109 layers is peeled off into 2 to 4 layers. If the sheet peels off causing the carbon to contain only one layer or several layers then this sheet is named graphene oxide (GO). GO is made through a modified Hummers process. GO is easily processed into reduced graphene oxide (rGO). Graphene oxide was reduced by glycine, ascorbic acid, and lemon extract as a green reducing agent. The results of the characterization of reduced graphene oxide showed that the results of the reduced graphene oxide were not steep in the wave range of 3100 to 3500 cm^-1 which indicated that the -OH bond was present, the wave was 1500-1600 cm^-1 which indicated that the bond was C=C, and the wave was 1000 to 1300 cm^-1 which indicates that the C-O bond; The green reducing concentration affects the C elements contained in rGO ranging from 82.81 to 85.33% and the O elements contained in rGO ranging from 8.60 to 14.85%."

"Azithromycin (AZI) adalah antibiotika yang digunakan secara luas. AZI merupakan obat yang memiliki spesifikasi kelarutan yang rendah dalam air serta memiliki nilai bioavailabilitas oral rendah yaitu sebesar 37%. Rendahnya kelarutan dan bioavailabilitas oral AZI dapat berdampak pada rendahnya efek terapetik obat tersebut. Teknik enkapsulasi dan sistem penghantar obat melalui nanocarrier adalah metode alternatif untuk meningkatkan bioavailabilitas obat yang memiliki kelarutan rendah dalam air. Nanopartikel kitosan (NPKS) adalah salah satu polimer yang paling umum digunakan sebagai penghantar obat. Pada penelitian ini nilai efisiensi enkapsulasi dan kapasitas pemuatan AZI pada NPKS berhasil ditingkatkan dengan memodifikasi NPKS menggunakan ekstrak daun binahong (EDB). Metabolit sekunder pada EDB dapat bereaksi dengan gugus amina pada NPKS dan meningkatkan sifat hidrofobiknya sehingga interaksi antara NPKS dengan AZI menjadi lebih baik. Hal tersebut dapat terlihat dari nilai efisiensi enkapsulasi dan kapasitas pemuatan AZI yang sangat baik untuk NPKS- EDB-AZI yaitu pada nilai 95,24 ± 1,30% dan 55,74 ± 1,03%. Hasil karakterisasi TEM menunjukkan bahwa NPKS-EDB-AZI terdistribusi secara homogen dengan ukuran partikel 24,6 ± 2,9 nm. Berdasarkan hasil uji pelepasan obat in vitro, NPKS-EDB-AZI melepaskan AZI sebesar 1,12 ± 0,33% ketika ditempatkan pada pH 1,6 selama 2 jam, 82,05 ± 2,23% pada pH 6,8 selama 6 jam, dan 93,44 ± 1,94% ketika ditempatkan pada pH 7,4 selama 16 jam. Penelitian ini menunjukan bahwa NPKS yang termodifikasi EDB dapat dimanfaatkan sebagai sistem penghantar azithromycin dengan nilai efisiensi pemuatan dan kapasitas pemuatan yang baik, serta memberikan sifat pelepasan obat secara terkontrol.

---

Azithromycin (AZI) is a widely used antibiotic. AZI is a drug that has a low solubility in water and a low oral bioavailability value of 37%. The low solubility and oral bioavailability of AZI can have an impact on the low therapeutic effect of the drug. Encapsulation techniques and drug delivery systems via nanocarriers are alternative methods to improve the bioavailability of drugs that have low solubility in water. Chitosan nanoparticles (NPKS) are one of the most commonly used polymers as drug conductors. In this study, the value of encapsulation efficiency and AZI loading capacity on NPKS was successfully increased by modifying NPKS using binahong leaf extract (EDB). Secondary metabolites in EDB can react with amine groups in NPKS and increase their hydrophobic properties so that the interaction between NPKS and AZI becomes better. This can be seen from the excellent encapsulation efficiency and AZI loading capacity values for NPKS-EDB-AZI, namely 95.24 ± 1.30% and 55.74 ± 1.03%. The results of TEM characterization showed that NPKS-EDB-AZI was homogeneously distributed with a particle size of 24.6 ± 2.9 nm. Based on the results of in vitro drug release tests, NPKS-EDB-AZI released AZI of 1.12 ± 0.33% when placed at pH 1.6 for 2 hours, 82.05 ± 2.23% at pH 6.8 for 6 hours, and 93.44 ± 1.94% when placed at pH 7.4 for 16 hours. This study shows that EDB-modified NPKS can be used as an azithromycin delivery system with good loading efficiency and loading capacity and controlled drug release properties.

"

"Pada penlitian ini telah berhasil disintesis nanokomposit LaCeO3/CuO dengan menggunakan metode sintesis hijau yang termediasi ekstrak daun pohon sosis (Kigelia Africana). Penggabungan material LaCeO3 dan CuO dilakuakan guna meningkatkan aktivitas fotokatalitik dalam mendegradasi malasit hijau (MH). LaCeO3/CuO dengan nilai celah pita 2,88 eV menunjukkan hasil yang berkesesuaian pada spektra FTIR, dengan munculnya puncak milik La-O, Ce-O dan Cu-O serta hasil XRD yang memiliki struktur gabungan LaCeO3 dan CuO. Morfologi yang teramati adalah berupa partikel berbentuk kuboik dengan ukuran partikel nano. Aktivitas fotokatalis dari LaCeO3/CuO menunjukkan persentase degradasi MH sebesar 92,88%. Penggunaan kembali material memberikan persentase degradasi yang cukup stabil yaitu pada 88,62% setelah 3 kali siklus, menunjukkan bahwa material memiliki kemampuan penggunaan kembali yang baik.

---

In this study, the LaCeO₃/CuO nanocomposite was successfully synthesized using a green synthesis method mediated by the extract of sausage tree leaves (Kigelia africana). The combination of LaCeO3 and CuO materials was carried out to enhance photocatalytic activity in degrading malachite green (MG). LaCeO3/CuO, with a bandgap value of 2.88 eV, showed consistent results in the FTIR spectra, with the appearance of peaks corresponding to La-O, Ce-O, and Cu-O bonds, as well as XRD results indicating the combined structure of LaCeO3 and CuO. The observed morphology consisted of cubic-shaped nanoparticles. The photocatalytic activity of LaCeO₃/CuO demonstrated a malachite green degradation percentage of 92.88%. The reuse of the material demonstrated a relatively stable degradation percentage of 88.62% after three cycles, indicating that the material possesses good reusability."

"Diabetes melitus merupakan penyakit hiperglikemia kronis yang dapat menyebabkan komplikasi hipoglikemia, hiperglikemia, komplikasi makrovaskular dan mikrovaskular. Alternatif pendekatan terapi untuk menormalkan kadar gula darah ialah inhibitor α-glukosidase. Namun, penggunaan inhibitor α-glukosidase menimbulkan efek samping gangguan gastrointestinal, maka dicari sumber dari tumbuhan agar lebih aman.Penelitian terdahulu menunjukkan ekstrak etanol dari herba meniran (Phyllanthus niruri L.) memiliki penghambatan aktivitas α-glukosidase yang kuat dengan IC50 = 2,32 μg/mL. Penelitian ini bertujuan mengetahui aktivitas penghambatan α-glukosidase terhadap fraksi teraktif hasil fraksinasi ekstrak metanol herba meniran dan mengetahui golongan senyawa kimia yang terdapat pada fraksi teraktif. Ekstrak metanol difraksinasi menggunakan fase diam Sephadex LH-20 dan fase gerak metanol 50%.Empat fraksi terpilih diuji penghambatan aktivitas α-glukosidase dengan menggunakan microplate reader. Didapatkan nilai IC50 dari fraksi teraktif adalah 37,257 μg/mL dan dilakukan uji kinetika penghambatan. Fraksi ini memiliki jenis penghambatan kompetitif terhadap α-glukosidase. Hasil penapisan fitokimia menunjukkan fraksi teraktif mengandung flavonoid dan tanin.

---

Diabetes mellitus is a hyperglycemia chronic disease that can lead to complications like hypoglycemia, hyperglycemia, macrovascular and microvascular complications. Alternative therapeutic approaches to normalize blood sugar levels are α-glucosidase inhibitor. However, utilization of α-glucosidase inhibitor has side effects like gastrointestinal disorders, then look for the source from plants to find more safety therapy.Past research has shown that the ethanolic extract from aerial part Phyllanthus niruri L. has strong α-glucosidase inhibitory activity with IC50 = 2.32 µg/mL. The aims from this study to determine the α-glucosidase inhibitory activity from the most active fractions of methanolic extracts Phyllanthus niruri L. as fractionation results and to know chemical compounds in the most active fraction. Methanolic extract fractionated using Sephadex LH-20 and 50% methanol as mobile phase.The four selected fractions tested α-glucosidase inhibitory activity using microplate reader. The IC50 values ​​was obtained from the most active fraction 37.257 µg/mL and tested kinetics inhibition. The fraction has mechanism competitive inhibition with α-glucosidase. The phytochemical screening showed that the most active fractions containing flavonoids and tannins."

"The primary aim of this research is to synthesis composite anthill-chicken eggshell catalyst, which is characterized and employed for the synthesis of biodiesel from waste frying oil. The as-synthesized catalyst was characterized using various characterization techniques, such as X-ray fluorescence (XRF), Fourier transform infrared radiation (FTIR), Brunauer–Emmett–Teller (BET) analysis, scanning electron microscopy (SEM), and Basicity. The influence of different reaction parameters on the catalytic reaction, reaction time, catalyst loading and reaction temperature in the range of 50–75°C were studied at fixed methanol/oil ratio of 6:1. The experimental data obtained showed that at reaction time of 2 h, catalyst loading of 5 wt% and reaction temperature of 60°C, the biodiesel yield was 70%. The synthesized catalyst was found to convert low-grade oil into biodiesel via a single-step transesterification process, and its activity has the potential for improvement."

"Pendahuluan: Barier alamiah berupa membrane sel, kompartemen endosom, dan membrane inti sel yang menghalangi DNA ekstraseluler untuk mencapai target kerja dalam inti sel dalam mengawali proses pembentukan protein transgen. Sistem penghantar DNA, dalam hal ini protein penghantar DNA (PPD) dikembangkan untuk menghindari penghalang seluler tersebut. Karena sel tubuh berada dalam keadaan tidak membelah, maka diharapkan PPD tersebut dapat berfungsi pada sel tidak membelah. Metodologi: Metodologi yang dipakai adalah telaah literature, pengkloningan, dan uji in vitro. Dilakukan telaah literature untuk mencari peptida yang memiliki 1) kemampuan untuk masuk ke dalam sel/ berfusi dengan membran sel hospes, 2) kemampuan mengikat DNA, 3) kemampuan menghantarkan DNA melalui nuclear localization signal (NLS). Sekuen protein diubah menjadi DNA dengan menggunakan perangkat lunak. Setelah menjadi fragmen DNA, maka langkah selanjutnya DNA di klon ke dalam plasmid pQE80L untuk menghasilkan plasmid rekombian pengekspresi PPD. PPD diperoleh dengan cara mengekspresikannya ke dalam sistem prokariota. Setelah PPD dimurnikan, dilakukan uji fungsi kemampuan PPD menghantarkan DNA pada sel kultur membelah dan tidak membelah. Hasil: Berdasarkan telaah literature dihasilkan 5 rancangan PPD ALMR, SIMR, VPMR, THB2 dan THB4. Studi bioinformatika menunjukkan THB4 tidak dapat mengikat DNA dan bergerak ke inti sel. Proses pengkloningan menghasilkan 4 klon dan salah satu dari 4 kandidat PPD, THB2, tidak dapat diekspresikan dalam prokariota. ALMR, SIMR dan VPMR memiliki kemampuan untuk mengikat DNA dan melindungi DNA dari efek nuclease. Uji in vitro menunjukkan hanya ALMR yang dapat menghantarkan pcDNA3.1eGFP ke inti yang ditandai oleh ekspresi transgen oleh CHOK1. Jika dibandingkan dengan Lipofectamine, efektivitas penghantaran DNA oleh ALMR pada sel membelah kurang efektif,namun penghantaran DNA oleh ALMR pada sel tidak membelah lebih efektif dibandingkan Lipofectamine. Penambahan ALMR ke dalam komplek Lipofectamine:DNA dapat meningkatkan efisiensi penghantaran DNA dan viabilitas sel. Kesimpulan: PPD yang dapat mengikat, melindungi, dan menghantarkan DNA ke dalam sel membelah dan tidak membelah telah berhasil diperoleh. Penggabungan PPD dengan lipofectamine dapat meningkatkan efisiensi dan efektivitas penghantaran DNA kedalam sel tidak membelah serta meningkatkan viabilitas sel tidak membelah pasca transfeksi.

---

Background: The journey of extracellular DNA to reach its active site, nucleus, is dependent on its capability to overcome cellular barriers such as cell membrane, endosomal compartment and nuclear membran. To overcome such natural barriers, we developed peptide-mediated DNA delivery system that could deliver DNA especially into non-dividing cells as the majority of human cells are found in nondividing state.

Methodology: Based on literature studies we found peptides that have capability 1) to translocate/fuse with cellular membrane, 2) to bind DNA and protect DNA from nuclease 3) as nuclear localization signal (NLS). We convert peptides into DNA sequences by using software. DNA coding peptide-mediated DNA delivery systems were synthesized by commercially and manually using conventional PCR. The DNA fragments were cloned into prokaryote-expression systems. After expression and purification, peptide-mediated DNA delivery systems were tested their capability to increase the efficiency and effectiveness of the transformation of extracellular DNA in dividing and non-dividing cells.

Result: We constructs 5 candidates of peptide-mediated delivery system. One of them has no capability to bind DNA and located using nucleus. One of the rest peptidemediated delivery system could not be expressed in prokaryote system. Furthermore, three candidates have capability to binds DNA and protect DNA from nuclease degradation. Based on in vitro study, only one candidate has the capability to deliver DNA pcDNA3.1 eGFP into CHOK1 nucleus that marked by the expression of transgen. Compared to the Lipofectamine, a commercial delivery system, the capability of ALMR to deliver DNA into dividing cell is less efficient, but the capability of ALMR to deliver DNA into non-dividing cells is more efficient compare to Lipofectamine. The addition of ALMR into lipofectamine-DNA complex could increasing both the percentage of transgeneexpressing cells and viability of cell.

Conclusions: We have gained one peptide-mediated delivery system that could bind, protect and deliver DNA from extracellular into intracellular environment of dividing and non dividing cells. The addition of peptide-mediated delivery into Lipofectamine could increase the efectivity of DNA transformation and increase the cell viability."

"Pachydermin, an oxylated tetramic acid with 3-chloro-4-hydroxyphenyl substituent, was isolated from Chamonixia pachydermis plant, a basidiomycete of New Zealand. Its degradation product exhibits antibacterial activity against Bacillus subtilis, and the derivatives of pachydermin are anticipated to have similar potentials. In this work, a novel approach to synthesize 3-methyl-5-nitrobenzyl β,β-diketoester was developed as a derivative of the natural product pachydermin. The synthetic route began with the synthesis of N-benzylated β,β-diketoester as the key structural moiety, from glycine methyl ester as the starting material. subsequently, oxalyl subunit was inserted, as well as other acyl/alkyl subunits at C-3 position of the β,β-diketoester ring via acylation/alkylation reactions leading to the required intermediates towards pachydermin and its derivatives. alkene functionalities at C-5 position could then be introduced using different alkyl or aryl aldehydes, with the aid of different bases which included diisopropylamine, NaH, Et3N, K2CO3 as well as ionic liquids. insertions of methyl and 4-nitrobenzylidene functionalities at C3- and C5-positions, respectively, were highlighted for the synthesis of the target derivative. selective decarboxylation, ester hydrolysis and N-benzyl deprotection should lead to the required target compound and derivatives. all the synthesized compounds were confirmed by the mass spectroscopy (MS) and nuclear magnetic resonance (NMR) spectroscopy."