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Small-Angle Neutron Scattering Study on Defect-Controlled Polymer Networks
Nishi, Kengo,Asai, Hanako,Fujii, Kenta,Han, Young-Soo,Kim, Tae-Hwan,Sakai, Takamasa,Shibayama, Mitsuhiro American Chemical Society 2014 Macromolecules Vol.47 No.5
<P>Tetra-PEG gels are classified to near-“ideal” networks with significantly low inhomogeneities, which were confirmed by small-angle neutron scattering (SANS). In this study, we systematically introduced two types of defects into Tetra-PEG gels and investigated effects of defects on structure. First, we prepared defect-rich networks by simply reducing prepolymer concentration, and observed the evolution of network structure by time-resolved SANS during gelation process. In this case, both the scattering intensity and the correlation length increased with reaction time in the ϕ < ϕ* region, while they scarcely changed in the ϕ > ϕ* region. Here, ϕ and ϕ* are the polymer volume fractions at observation and that at chain-overlap concentration, respectively. Second, we prepared “<I>p</I>-tuned” Tetra-PEG gels by tuning the reaction probability, <I>p</I>, and soaked them in water to expose the inhomogeneities. It was revealed that SANS profiles of as-prepared gels did not change noticeably, while those of swollen gels systematically changed with decreasing <I>p</I>. On the basis of these results, we discuss the relationship between the defects of polymer network and inhomogeneities by using simple schematic pictures of polymer network.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/mamobx/2014/mamobx.2014.47.issue-5/ma402590n/production/images/medium/ma-2013-02590n_0009.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ma402590n'>ACS Electronic Supporting Info</A></P>
Kuroda, Shinnosuke,Kondo, Takuya,Mori, Kohei,Yasuda, Kengo,Asai, Takuo,Sanjo, Hiroyuki,Yakanaka, Hiroyuki,Takeshima, Teppei,Kawahara, Takashi,Kato, Yoshitake,Miyoshi, Yasuhide,Uemura, Hiroji,Iwasaki, The Korean Society for Reproductive Medicine 2018 Clinical and Experimental Reproductive Medicine Vol.45 No.1
Onco-testicular sperm extraction is used to preserve fertility in patients with bilateral testicular tumors and azoospermia. We report the case of a testicular tumor in the solitary testis of a patient who had previously undergone successful contralateral orchiectomy and whose sperm was preserved by onco-testicular sperm extraction. A 35-year-old patient presented with swelling of his right scrotum that had lasted for 1 month. His medical history included a contralateral orchiectomy during childhood. Ultrasonography revealed a mosaic echoic area in his scrotum, suggesting a testicular tumor. The lesion was palpated within the normal testicular tissue along its edge and semen analysis showed azoospermia. Radical inguinal orchiectomy and onco-testicular sperm extraction were performed simultaneously. Motile spermatozoa were extracted from normal seminiferous tubules under microscopy and were frozen. Eventual intracytoplasmic sperm injection using the frozen spermatozoa is planned. Onco-testicular sperm extraction is an important fertility preservation method in patients with bilateral testicular tumors or a history of a previous contralateral orchiectomy.
Kuroda, Shinnosuke,Usui, Kimitsugu,Mori, Kohei,Yasuda, Kengo,Asai, Takuo,Sanjo, Hiroyuki,Yakanaka, Hiroyuki,Takeshima, Teppei,Kawahara, Takashi,Hamanoue, Haruka,Kato, Yoshitake,Miyoshi, Yasuhide,Uemur The Korean Society for Reproductive Medicine 2018 Clinical and Experimental Reproductive Medicine Vol.45 No.1
We report the case of a 46-year-old Chinese male patient who visited our clinic complaining of infertility. Semen analysis revealed azoospermia, and azoospermia factor c region partial deletion (b1/b3) was detected using Y chromosome microdeletion analysis. Testicular sperm extraction was performed after genetic counseling. The bilateral ductus deferens and a portion of the epididymis were absent, whereas the remaining epididymis was expanded. Motile intratesticular spermatozoa were successfully extracted from the seminiferous tubule. On histopathology, nearly complete spermatogenesis was confirmed in almost every seminiferous tubule. To our knowledge, this is the first case report of b1/b3 deletion with a congenital bilateral absence of the vas deferens and almost normal spermatogenesis.