Current "hybrid closed-loop systems" use a continuous glucose monitor to sense blood sugar levels, and a subcutaneous insulin pump to deliver insulin; however, due to the delay between insulin injection and its action, current systems require the user to initiate insulin before taking meals. Several improvements to these systems are currently undergoing clinical trials in humans, including a dual-hormone system that injects glucagon in addition to insulin, and an implantable device that injects insulin intraperitoneally where it can be absorbed more quickly. Disease models
Various animal models of disease are used to understand the pathogenesis and etiology of type 1 diabetes. Currently available models of T1D can be divided into spontaneously autoimmune, chemically induced, virus induced and genetically induced.The nonobese diabetic (NOD) mouse is the most widely studied model of type 1 diabetes. It is an inbred strain that spontaneously develops type 1 diabetes in 30–100% of female mice depending on housing conditions. Diabetes in NOD mice is caused by several genes, primarily MHC genes involved in antigen presentation. Like diabetic humans, NOD mice develop islet autoantibodies and inflammation in the islet, followed by reduced insulin production and hyperglycemia. Some features of human diabetes are exaggerated in NOD mice, namely the mice have more severe islet inflammation than humans, and have a much more pronounced sex bias, with females developing diabetes far more frequently than males. In NOD mice the onset of insulitis occurs at 3–4 weeks of age.
In phonetics, denasalization is the loss of nasal airflow in a nasal sound, such as a nasal consonant or a nasal vowel. That may be due to speech pathology but also occurs when the sinuses are blocked from a common cold, when it is called a nasal voice, which is not a linguistic term. Acoustically, it is the "absence of the expected nasal resonance." The symbol in the Extended IPA is ⟨◌͊⟩. When one speaks with a cold, the nasal passages still function as a resonant cavity so a denasalized nasal [m͊] does not sound like a voiced oral stop [b], and a denasalized vowel [a͊] does not sound like an oral vowel [a]. However, there are cases of historical or allophonic denasalization that have produced oral stops. In some languages with nasal vowels, such as Paicĩ, nasal consonants may occur only before nasal vowels; before oral vowels, prenasalized stops are found. That allophonic variation is likely to be from a historical process of partial denasalization. Similarly, several languages around Puget Sound underwent a process of denasalization about 100 years ago. Except in special speech registers, such as baby talk, the nasals [m, n] became the voiced stops [b, d]. It appears from historical records that there was an intermediate stage in which the stops were prenasalized stops [ᵐb, ⁿd] or poststopped nasals [mᵇ, nᵈ]. Something similar has occurred with word-initial nasals in Korean; in some contexts, /m/, /n/ are denasalized to [b, d].