Judul: Peranan Kopi Dekafeinasi dalam Menurunkan Risiko Hipertensi : Sebuah Tinjauan Sistematis
Abstrak: Hypertension or increased blood pressure is a degenerative disease with a high prevalence, as well as the biggest cause of premature death in the world. Meanwhile, coffee is a popular and most consumed beverage around the world. Coffee can harm some people with certain health problems including hypertension due to its caffeine content. Decaffeinated coffee is known to be an alternative for people with hypertension with reduced caffeine content up to 97%. However, studies on the role of decaffeinated coffee in decreasing the risk of hypertension are still varied, indicated a systematic review is needed. This study uses a systematic review method to summarize the evidence related to the effect of decaffeinated and regular coffee on the risk of hypertension using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The inclusion criteria for scientific journals were determined based on Participants, Intervention, Control, Outcome (PICO). The search using boolean operation resulted in 13 research articles for data extraction. The result revealed that decaffeinated coffee varied between it could decrease or did not give any effect on blood pressure or another biological hypertension marker compared to regular coffee., Hipertensi atau peningkatan tekanan darah merupakan penyakit degeneratif dengan prevalensi tinggi, sekaligus penyebab kematian dini terbesar di dunia. Sedangkan kopi merupakan minuman yang populer dan paling banyak dikonsumsi di seluruh dunia. Kopi dapat membahayakan sebagian orang dengan masalah kesehatan tertentu termasuk hipertensi karena kandungan kafeinnya. Kopi tanpa kafein diketahui bisa menjadi alternatif bagi penderita hipertensi dengan kandungan kafein yang berkurang hingga 97%. Namun, penelitian tentang pengaruh kopi dekafeinasi dalam menurunkan risiko hipertensi masih bervariasi, mengindikasikan perlu dilakukan tinjauan sistematis. Penelitian ini menggunakan metode tinjauan sistematis untuk meringkas hasil penelitian terkait efek kopi tanpa kafein dan kopi biasa terhadap risiko hipertensi menggunakan Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Kriteria inklusi untuk jurnal ilmiah ditentukan berdasarkan Peserta, Intervensi, Pengendalian, Hasil (PICO). Pencarian menggunakan operasi boolean menghasilkan 13 artikel penelitian untuk ekstraksi data. Hasil penelitian menunjukkan bahwa kopi tanpa kafein memberikan efek yang bervariasi antara dapat menurunkan atau tidak berpengaruh pada tekanan darah atau penanda hipertensi biologis lainnya dibandingkan kopi biasa.
Keyword: Coffee, Decaffeinated coffee, Hypertension, Systematic review, Regular coffee

Judul: The relationship between coffee consumption and blood  pressure in the outpatient at Bogor Tengah community health center
Abstrak: The objective of this research was to study the relationship pattern of coffee consumption with the incidence of hypertension in outpatient Bogor Tengah Community Health Center. The design of this study was Case Control in the ratio of cases and controls were 1:1 with a total of 160 subjects. The control subjects were defined who had blood pressure ≤120/≤80 mmHg, while the cases subjects had blood pressure ≥140/≥90 mmHg based on the doctor's diagnosis at least 1 month previously. Pattern coffee consumption data was collected through interviews using a questionnaire containing 15 questions. The habit of drinking coffee in the case group decreased after being diagnosed hypertension and showed a statistically significant difference (p<0,05). Coffee consumption more than 7 cups per week there is not statistically significant with the hypertension (OR=0,677; 95% CI: 0,333–1,378) (p>0,05).
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Judul: Penentuan Nilai Eigen dan Vektor Eigen dari Matriks Tridiagonal 2-Toeplitz dengan Pendekatan Polinomial Chebyshev
Abstrak: The eigenvalues and eigenvectors of a matrix can be determined by finding its characteristic polynomials. The characteristic polynomials of a tridiagonal 2-Toeplitz matrix is shown to be closely connected to polynomials which satisfy the Chebyshev recurrence relationship. If the order of the matrix is odd, then the eigenvalues are found explicitly in terms of the Chebyshev zeros and the eigenvectors are found in terms of the polynomials satisfying the recurrence relationship. For even ordered matrices, the situation is more complicated. The problem in these cases is that although the Chebyshev recurrence formula is still applied, its initial values are not generating Chebyshev polynomials
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