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Additional file 1. Table S1. Sociodemographic characteristics of participants who had reported current fertility problems according to the status of medical help-seeking. Table S2. Logistic regression analysis for factors associated with medical help-seeking among participants who had reported current fertility problems.

Table S1. ORs and 95% CIs of different thresholds for sperm concentrations for major birth defects among IVF cycles for which semen parameters were available (nâ =â 28,958â cycles). (DOCX 103 kb)

Table S5. ORs and 95% CIs of different thresholds for sperm motility for major birth defects among ICSI cycles for which semen parameters were available (nâ =â 24,010â cycles). (DOCX 131 kb)

Table S2. ORs and 95% CIs of different thresholds for sperm concentrations for major birth defects among ICSI cycles for which semen parameters were available (nâ =â 24,010â cycles). (DOCX 106 kb)

Table S4. ORs and 95% CIs of different thresholds for sperm motility for major birth defects among IVF cycles for which semen parameters were available (nâ =â 28,958â cycles). (DOCX 122 kb)

Table S3. ORs and 95% CIs for major birth defects among ICSI cycles with normal semen concentration and motility (nâ =â 34,839â cycles). (DOCX 109 kb)

The present study aimed to measure the levels of coagulation factors in stored whole blood of pregnant women and to determine their usefulness in treating pregnant women who developed coagulopathy. A prospective study to measure coagulation factors in stored donated whole blood from pregnant and non-pregnant women was conducted. Fibrinogen, FV, FVII, FVIII, FXIII, and von Willebrand factor were measured in blood stored at 4°C for 0, 1, 3, and 5 weeks. All coagulation factors except for factor XIII decreased during storage. Fibrinogen and factor VII in the blood collected from pregnant women gradually decreased over time and their levels were significantly higher after 5 weeks of storage than those of nonpregnant women at week 0. Whole blood donated by pregnant women for autologous blood transfusion and stored at 4°C may be expected being effectively for the prevention of coagulopathy and the treatment of circulatory blood volume loss.

To determine the efficacy of computed tomography (CT) attenuation of cystic lesions measured on an image browsing system to distinguish abscess from hematoma in women with acute abdomen. The medical records of female patients of reproductive age with acute abdomen who were treated over a 7-year period in a single center and who had undergone laparotomy or laparoscopic surgery and preoperative pelvic CT scanning were retrospectively analyzed to identify those with hematoma or abscess cyst formation. Nineteen patients with tubo-ovarian abscess (abscess group) and six patients with hematoma (hematoma group) formation in the pelvis were included in the analysis. The preoperative CT images of the tubo-ovarian cyst were retrospectively investigated on the basis of cyst attenuation. CT attenuation of the cyst measured by both two gynecologists could be used to clearly distinguish inflammatory disease with abscess formation from bleeding disease with hematoma. CT attenuation on a picture archiving and communication system can distinguish hematoma from abscess in women with acute abdomen. This may significantly contribute to making differential diagnosis without interpretation by a medical radiologist.

Endometrial decidualization represents an essential step for the successful implantation of the embryo; however, the molecular mechanism behind this differentiation process remains unclear. This study aimed to identify novel microRNAs (miRNAs) involved in the regulation of decidual gene expression in human endometrial stromal cells (HESCs). An in vitro analysis of primary undifferentiated and decidualizing HESCs was conducted. HESCs were isolated from hysterectomy specimens from normally cycling premenopausal women with uterine fibroids, who were not on hormonal treatment at the time of surgery. Primary HESCs were expanded in culture and decidualized with 8-bromo-cyclic adenosine monophosphate and medroxyprogesterone acetate. Microarray analysis identified six miRNAs differentially expressed in response to decidualization of HESCs. All but one miRNA were downregulated upon decidualization, including miR-542-3p. We demonstrated that miR-542-3p overexpression inhibits the induction of major decidual marker genes, including IGFBP1, WNT4 and PRL. In addition, miR-542-3p overexpression inhibited the morphological transformation of HESCs in response to deciduogenic cues. A luciferase reporter assay confirmed that the 3'-untranslated region of IGFBP1 mRNA is targeted by miR-542-3p. The results suggest that miR-542-3p plays an important role in endometrial decidualization by regulating the expression of major decidual marker genes.

Free fetal DNA (ffDNA) in maternal plasma has now become a valuable source for noninvasive prenatal diagnosis. Being able to accurately identify the size of ffDNA in maternal plasma is essential for a noninvasive prenatal diagnosis. Furthermore, it is important to investigate the molecular characteristics related to apoptosis which gives rise to ffDNA. We investigated the fragment size of ffDNA in each sample more precisely, using both Y-STR and SRY primers, in 20 maternal plasma samples from the 17th to 39th weeks of gestation. PCR was conducted with Y-STR and SRY primers which can be used to amplify 100–524 bp fragments. In samples from 10 pregnant women carrying male fetuses, the maximum fragment size detected by Y-STR and SRY primers ranged from 219 to 313 bp. As a result, the mean average maximum fragment size of free fetal DNA detected by Y-STR and SRY primers was 286±28 bp. The Y-STR alleles detected in each maternal plasma DNA sample were all in agreement with the results of their cord blood samples. We concluded that the fragment size of ffDNA comprises 2 nucleosomal complexes or less, but not exceeding 3.

Free fetal DNA (ffDNA) in maternal plasma has now become a valuable source for noninvasive prenatal diagnosis. Being able to accurately identify the size of ffDNA in maternal plasma is essential for a noninvasive prenatal diagnosis. Furthermore, it is important to investigate the molecular characteristics related to apoptosis which gives rise to ffDNA. We investigated the fragment size of ffDNA in each sample more precisely, using both Y-STR and SRY primers, in 20 maternal plasma samples from the 17th to 39th weeks of gestation. PCR was conducted with Y-STR and SRY primers which can be used to amplify 100–524 bp fragments. In samples from 10 pregnant women carrying male fetuses, the maximum fragment size detected by Y-STR and SRY primers ranged from 219 to 313 bp. As a result, the mean average maximum fragment size of free fetal DNA detected by Y-STR and SRY primers was 286±28 bp. The Y-STR alleles detected in each maternal plasma DNA sample were all in agreement with the results of their cord blood samples. We concluded that the fragment size of ffDNA comprises 2 nucleosomal complexes or less, but not exceeding 3.

平成20年度スペース・プラズマ研究会(2009年3月5日-6日, 宇宙航空研究開発機構宇宙科学研究本部), 資料番号: AA0064296023

2006年に実施した妊婦を対象とする葉酸認知率と, サプリメント摂取率の調査, 食事記録票の分析データを報告した。1251通のアンケート調査を分析した結果, 1)葉酸サプリメントが二分脊椎症を防止することを認識していたのは35%で, 高学歴群と高年齢群はそれぞれの対照群と比較してより多くがこの情報を承知していた。2)情報の入手源はマスメディアまたはインターネットと回答しており, 医療職からとの回答は13%であった。3)葉酸サプリメントの摂取率は認知率よりやや低かったが, アンケートに触発されて17%の妊婦が前向きの回答をしていた。4)86枚の食事記録票の分析では, 妊婦が摂取している葉酸は平均341μg/日で, 厚生労働省が推奨・期待する400μg/日には約60μg/日不足しており, 妊娠期別では妊娠前期が最も低値を示していた。尚, 400μg/日を満す妊婦は18%で, その中の4人はサプリメントも内服していた。不足していた82%のうち, 34%は葉酸サプリメントを内服していた。, Folic acid plays an important role in proliferating cells and tissues of the fetus. A randomized control trial demonstrated in 1991 that 4 mg of folic acid supplements successfully prevented 72% of recurrence of neural tube defects (NTDs) in women who had had afflicted pregnancy. In 2000, the Japanese Government recommended women of childbearing age to take 400 microgram of folate supplements per day from 4 weeks prior to and 12 weeks after conception. A questionnaire study was performed in pregnant women by post on their awareness of the role folic acid plays, their life style, and folate intake by dietary consumption. Thirty-five percent of 1, 251 pregnant women were aware of the important role of folic acid in the critical stage of fetal development and 31% actually took the supplement. Information on folic acid was obtained through mass media in 47% of the women, through the internet in 17%, through healthcare providers in 13% and so forth. The food record analysis revealed that the dietary intake of folic acid averaged 341 microg/day that was 60 microg less than what was recommended by the Government and that 33 of 86 women took the supplement. Overall, a half of pregnant women are required to take 400 microg folate supplement per day. It is to be stressed that primary prevention of NTDs by periconceptional intake of folic acid is a major public health opportunity and that prevention is more important than cure in the management of NTDs.

平成19年度スペースプラズマ研究会 (2008年3月27日-28日. 宇宙航空研究開発機構宇宙科学研究本部(JAXA)(ISAS)相模原キャンパス), 相模原市, 神奈川県, Space Plasma Conference FY2007 (March 27-28, 2008. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)), Sagamihara, Kanagawa Japan, 資料番号: SA6000113021

平成19年度スペースプラズマ研究会 (2008年3月27日-28日. 宇宙航空研究開発機構宇宙科学研究本部(JAXA)(ISAS)相模原キャンパス), 相模原市, 神奈川県, Space Plasma Conference FY2007 (March 27-28, 2008. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)), Sagamihara, Kanagawa Japan, 資料番号: SA6000113025

資料番号: SA1003595000

平成18年度スペースプラズマ研究会 (2007年3月22日-23日. 宇宙航空研究開発機構宇宙科学研究本部(JAXA)(ISAS)相模原キャンパス), 相模原市, 神奈川県, Space Plasma Conference FY2006 (March 22-23, 2007. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)), Sagamihara, Kanagawa Japan, 資料番号: SA6000114004

平成17年度スペース・プラズマ研究会 (2006年3月16日-17日. 宇宙航空研究開発機構宇宙科学研究本部(JAXA)(ISAS)相模原キャンパス), 相模原市, 神奈川県, Space Plasma Conference FY2005 (March 16-17, 2006. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)), Sagamihara, Kanagawa Japan, 資料番号: SA6000115014

平成17年度スペース・プラズマ研究会 (2006年3月16日-17日. 宇宙航空研究開発機構宇宙科学研究本部(JAXA)(ISAS)相模原キャンパス), 相模原市, 神奈川県, Space Plasma Conference FY2005 (March 16-17, 2006. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)), Sagamihara, Kanagawa Japan, 資料番号: SA6000115003

フェルミ加速を調べるために、電子が振動するポテンシャル壁と定常なポテンシャル障壁の間を磁場に沿って往復運動する新しい実験系を考案した。この実験で、電子が共鳴的に加速するときのポテンシャル障壁の振動の周波数は、電子の往復運動の周波数に関係していることが観測できた。さらに、電子の加速エネルギーと電子がポテンシャル壁の間を往復運動する回数との関係も測定した。, To study Fermi acceleration, a novel experimental system, where electrons go back and forth along a magnetic field line between an oscillating potential wall and a stationary potential wall, has been constructed and the resonance of electron's bounce motion with the oscillation was observed. The relation of the number of bounce time with electron's acceleration energy was also measured., 資料番号: AA0049213003, レポート番号: JAXA-SP-05-020

資料番号: AA0047901011

資料番号: AA0045919005

平成24年度スペースプラズマ研究会(2013年2月26-27日. 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS)相模原キャンパス), 相模原市, 神奈川県, Space Plasma Conference FY2012 (February 26-27, 2013. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency(JAXA)(ISAS)Sagamihara Campus), Sagamihara, Kanagawa Japan, 資料番号: SA6000078010

平成23年度スペースプラズマ研究会(2012年2月27-28日. 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS)相模原キャンパス), 相模原市, 神奈川県, Space Plasma Conference FY2011 (February 27-28, 2012. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency(JAXA)(ISAS)Sagamihara Campus), Sagamihara, Kanagawa Japan, 資料番号: SA6000079042

平成23年度スペースプラズマ研究会(2012年2月27-28日. 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS)相模原キャンパス), 相模原市, 神奈川県, Space Plasma Conference FY2011 (February 27-28, 2012. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency(JAXA)(ISAS)Sagamihara Campus), Sagamihara, Kanagawa Japan, 資料番号: SA6000079041

平成22年度スペースプラズマ研究会(2011年3月3-4日. 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS)相模原キャンパス), 相模原市, 神奈川県, Space Plasma Conference FY2010 (March 3-4, 2011. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency(JAXA)(ISAS)Sagamihara Campus), Sagamihara, Kanagawa Japan, 資料番号: SA6000080019

平成22年度スペースプラズマ研究会(2011年3月3-4日. 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS)相模原キャンパス), 相模原市, 神奈川県, Space Plasma Conference FY2010 (March 3-4, 2011. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency(JAXA)(ISAS)Sagamihara Campus), Sagamihara, Kanagawa Japan, 資料番号: SA6000080037

平成21年度スペースプラズマ研究会(2010年3月11-12日, 宇宙航空研究開発機構宇宙科学研究本部), Space Plasma Conference(March 11-12, 2010, Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Sagamihara, Japan), 形態: CD-ROM1枚, Note: One CD-ROM, 資料番号: AA0064740025

平成21年度スペースプラズマ研究会(2010年3月11-12日, 宇宙航空研究開発機構宇宙科学研究本部), Space Plasma Conference(March 11-12, 2010, Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Sagamihara, Japan), 形態: CD-ROM1枚, Note: One CD-ROM, 資料番号: AA0064740017

2007年12月19日および2008年12月16日開催の研究会における講演より10編の査読論文を収録, Space Plasma Symposium FY2007 and FY2008, A brand-new experimental device, which is named YCOPEX (Yokohama Complex Plasma Experiments) suitable for two-dimensional wide area complex plasma experiments, designed by Nakamura and Ishihara. (Rev. Sci. Instrum., 79, (2008) 033504), is introduced. To show its high potential for complex plasma experiments with/without dusty-plasma flows, several qualitative experiments are presented such as void formation around a biased obstacle, three states of dusty plasmas around the obstacle, and a possibility to excite a dustyplasma turbulence., 形態: カラー図版あり, Physical characteristics: Original contains color illustrations, 資料番号: AA0064669010, レポート番号: JAXA-RR-09-003

第26回宇宙利用シンポジウム(2010年1月25日-26日, 宇宙航空研究開発機構宇宙科学研究本部相模原キャンパス), The Twenty-sixth Space Utilization Symposium (January 25-26, 2010: ISAS/JAXA Sagamihara, Japan), The Pre-Phase A has been started from this fiscal year. The main aim in this fiscal year is to advance development of a PK-4-like apparatus. Unfortunately, the schedule of the Pre-Phase A is delayed from 2 years to 3 years in total due to the lack of budget. The bipolar square wave generator with +/-1.5 kV and 10 mA at maximum is developed for the glow discharge in this fiscal year., 共催: 日本学術会議, 著者人数: 11人, joint hosting: The Science Council of Japan, 資料番号: AA0064730006

第26回宇宙利用シンポジウム(2010年1月25日-26日, 宇宙航空研究開発機構宇宙科学研究本部相模原キャンパス), The Twenty-sixth Space Utilization Symposium (January 25-26, 2010: ISAS/JAXA Sagamihara, Japan), The proposal of the experiment of observation of critical phenomena in a fine particle plasma was accepted as an experiment using the PK-3 Plus plasma equipment in the ISS Russian module. The experiments has been and is carried out in July, 2009 and in January, 2010. Along with the experiments using the PK-3 Plus, we are planning and developing new fine-particle plasma systems. By the use of a planar-magnetron plasma system, which is one of the new fine-particle plasma systems, drop-tower microgravity experiment was carried out., 形態: カラー図版あり, 共催: 日本学術会議, Physical characteristics: Original contains color illustrations, joint hosting: The Science Council of Japan, 資料番号: AA0064730005

第25回宇宙利用シンポジウム(2009年1月14日-15日, 宇宙航空研究開発機構宇宙科学研究本部相模原キャンパス), The Twenty-fifth Space Utilization Symposium (January 14-15, 2009: ISAS/JAXA Sagamihara, Japan), The main aim of this science working group this year is to revise candidates of future microgravity experiments in the region of complex plasmas. For the main aim, members of this working group reported their interests and discussed them. After selection of the candidates, we discussed the action plan., 資料番号: AA0064297114

第25回宇宙利用シンポジウム(2009年1月14日-15日, 宇宙航空研究開発機構宇宙科学研究本部相模原キャンパス), The Twenty-fifth Space Utilization Symposium (January 14-15, 2009: ISAS/JAXA Sagamihara, Japan), In order to verify the existence of critical point in a fine particle plasma, we are carrying out theoretical analysis and experiments using an experimental model of the PK-3 Plus system that is installed in ISS. Along with the experiments, we are also developing a new plasma system, which applies planar magnetron plasma. Preliminary experiments with the new system under gravity showed the generation of a loop of plasma and the potentiality of the generation without the formation of a "void" of fine particles under microgravity., 形態: カラー図版あり, 資料番号: AA0064297115

第22回宇宙利用シンポジウム(2006年1月17日-19日, 日本学術会議6階会議室 六本木、東京), The Twenty-second Space Utilization Symposium (January 17-19, 2006: Science Council of Japan, Roppongi, Tokyo, Japan), Study on fine particles plasmas is related to a variety of fields of research. Fine particle plasma is a kind of strongly coupled plasma and is predicted to take the critical phenomenon. Such a kind of interesting experiment is now planning to be performed under microgravity condition by the collaboration between German and Japanese research groups., 共催: 日本学術会議, 著者人数: 13人, Meeting sponsors: The Science Council of Japan, The Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (ISAS)(JAXA), 資料番号: AA0064113051

第28回宇宙利用シンポジウム (2012年1月23-24日. 日本学術会議), 港区, 東京都, Space Utilization Research (January 23-24, 2012. Science Council of Japan), Minato-ku, Tokyo Japan, 著者人数: 14名, 資料番号: SA6000032010, レポート番号: M10

第27回宇宙利用シンポジウム (2011年1月24日-25日, 宇宙航空研究開発機構宇宙科学研究所相模原キャンパス), 相模原市, 神奈川県, The Twenty-seventh Space Utilization Symposium (January 24-25, 2011. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)), Sagamihara, Kanagawa Japan, Fine particle plasmas serve as a unique and otherwise-difficult-to-realize system where effects of strong coupling can be analyzed directly on the particle level. A drawback is the large mass of fine particles and the microgravity environment enables us to perform ideal experiments. On the International Space Station (ISS), the facility PK-3Plus for fine particle plasma experiments has been operated by Max-Planck Institute for Extraterrestrial Physics (MPE) and Joint Institute for High Temperatures (JIHT). As the next-generation facility, the launch of PK-4 has been planned and experimental tests have been done on the ground and on the air plane (parabolic flights). The purpose of this Working Group is to propose appropriate themes for PK-4. The main part of PK-4 is a long straight discharge tube where the plasma with the cylindrical symmetry can be generated. By the activity of previous years, we have analyzed the behavior of strongly coupled fine particles with the cylindrical symmetry such as formation of Coulomb crystals by the theory and simulations. In this fiscal year, we are finishing the construction of the PK-4-J (a Japanese version facility which has the same dimension as PK-4) and expecting to obtain the basic data under microgravity by parabolic flights in March., 著者人数: 14人, 形態: カラー図版あり, Number of authors: 14, Physical characteristics: Original contains color illustrations, 資料番号: AA0065129006

第27回宇宙利用シンポジウム (2011年1月24日-25日, 宇宙航空研究開発機構宇宙科学研究所相模原キャンパス), 相模原市, 神奈川県, The Twenty-seventh Space Utilization Symposium (January 24-25, 2011. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)), Sagamihara, Kanagawa Japan, Plans next to PK-3 Plus for experiments of fine-particle plasma in International Space Station are proceeding in Europe. One of the plans, Plasma Lab (PK-5), is to develop and use the spherical distribution of fine particles without a void in a plasma. We are developing plasma systems for the purpose in collaboration with the group of Europe. In this budget year, we investigated to make spherical plasma configuration using a spherical quartz vessel and external radio-frequency electrode and managed to form particle arrangement without a void. We also carried out plasma diagnostics in a planar-magnetron radio-frequency plasma., 著者人数: 12人, 形態: カラー図版あり, Number of authors: 12, Physical characteristics: Original contains color illustrations, 資料番号: AA0065129005

The experimental verification of existence of critical point in a fine particle plasma is a exciting subject. It is being carried out under microgravity condition in ISS (International Space Station) by the collaboration among German, Russian and Japanese research groups. The results of preliminary experiments using a PK-3 Plus experimental model and a planar magnetron plasma system are also presented., 資料番号: AA0063706033

Fine particle plasma is a kind of one component plasmas and strongly coupled plasmas and is predicted to have the critical point. The experimental verification of existence of such a kind of interesting phenomena is now planning to be performed under microgravity condition by the collaboration between German and Japanese research groups., 資料番号: AA0063349060

平成17年度スペース・プラズマ研究会 (2006年3月16日-17日. 宇宙航空研究開発機構宇宙科学研究本部(JAXA)(ISAS)相模原キャンパス), 相模原市, 神奈川県, Space Plasma Conference FY2005 (March 16-17, 2006. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)), Sagamihara, Kanagawa Japan, 資料番号: SA6000115005

すまいの設備でも特に,水まわりの話題を中心に述べる。

我々のすまいの気密性が良くなった事に関連して，考慮しなければならなくなった，換気や結露について，その原因や注意点について述べる。

熊本の気候の特徴を考えながら,自然を生かした快適なすまいについて述べる。

我が国のエネルギー事情の概要について述べた後,ローカルエネルギー開発の意義を考えてみる。さらに具体例として,「熊本県における地域エネルギー開発利用調査報告書」を紹介し,熊本県のエネルギー事情の現状と将来を考える。最後に,ローカルエネルギーの主役とも言われる太陽熱利用に関して,身近かな例を用いて,その効率や経済性について検討する。

The purpose of this theoretical endeavor is to utilize the particle-in-cell (PIC) code called MAGIC to simulate the experimental work of the Plasma Edge Cathode (PEC). The PEC experiment investigates the transverse extraction of electrons from a plasma jet. The computer code MAGIC is a FORTRAN program that was written by Mission Research Corporation. The Air Force Office of Scientific Research (AFOSR) is funding the PEC experiment and is also currently funding the continued development of MAGIC. The Department of Electrical Engineering at Texas Tech University became an official MAGIC user along with five other academic and research oriented organizations in the latter part of 1988. This report discusses the results of using MAGIC to simulate the aforementioned experiment. The simulation work was accomplished by utilizing the University's computer network. This network allows the MAGIC user to run the code from any network connected computer. The MAGIC code resides on two campus computers, i.e., the VAX 8650 / VAX 11/780 cluster at the Advanced Technology Learning Center (A TLC) and the College of Engineering's (COE) Sun 4/280 RISC machine located in the COE office. The VAX cluster, which is operated and maintained by Academic Computing Services, was utilized for the majority of this simulation work since the Sun 4/280 was not configured to run MAGIC until August, 1990. MAGIC accurately simulated the PECina simulation that extracted electrons from a plasma of density equal to 9 x 1010 cm·3 at an extraction voltage of 23 kV across a 10 mm extraction gap. The extracted electron beam current density found from the simulation is about 8 A/ cm2 . This current density agrees quiet well with the Child-Langmuir law of space-charge-limited current in a planar diode.