关于2n和n在减数分裂中用法的商榷

在科学研究论文、高中生物、大学细胞生物学和遗传学减数分裂教学中,减数分裂I终变期细胞中的染色体数目的表示是用n还是用2n,目前还比较混乱,有的用n表示,但也有的用2n表示。该文通过对减数分裂I终变期细胞染色体行为和数目的分析,认为减数分裂I终变期细胞中的染色体数目应该用2n表示。     

2n/4n嵌合体胚胎的发育特点及其应用

2n/4n嵌合体是指用二倍体的胚胎细胞和四倍体的胚胎细胞聚合所形成的嵌合体。这种嵌合体在胚胎的发育过程中。四倍体来源的细胞在分布上具有一定的倾向性,即倾向于分布在胚外组织,如胎盘;而在胎儿本身的组织中,很少能找到四倍体细胞的存在,就2n/4n嵌合体胚胎的制作、嵌合体胚胎的发育特点及该技术的可能应用进行了综述。     

用2n作母本,用4n作父本也能产生3n西瓜种子吗?

高中《生物》课本 P150上,谈到三倍体西瓜的培育过程。其中有这样一段话:“……用四倍体植株作母本,用二倍体植株作父本,进行交配,就能在四倍体植株上结出三倍体西瓜的种子。”对此,不少师生提出另一种设想:如果反过来,用二倍体(2n)植株作母本,用四倍体     

Evaluación de la realización del cribado del pie diabético en Atención Primaria

AimTo ascertain whether patients with type 2 diabetes are screened for diabetic foot, and to analyze the factors related to patients and centers associated to performance of such screening.Material and methodsA multicenter, epidemiological, cross-sectional study was conducted. The clinical records of 443 patients with type 2 diabetes monitored at Primary Care for at least 12 months were reviewed. Demographic and healthcare variables and characteristics of the primary care center were recorded.ResultsIn the previous year, 51.2% of patients had been trained on foot self-care, 56.4% had undergone foot inspection, 39.5% had been examined with a monofilament, and palpation of peripheral pulses and measurement of the ankle-brachial index were performed in 45.8 and 10.1% of patients, respectively. Diabetic foot screening (inspection, monofilament testing, and palpation of peripheral pulses) was performed in 37% of study patients. Ulcer risk stratification was done in 12.4% of patients. A significant association was found between diabetic foot screening and presence of foot deformities (P < .001), history of neuropathy (P = .005), and history of peripheral artery disease (P < .05). Screening was also associated to some characteristics of the center, such as reception of information about goal achievement (P < .001) and economic incentives for goal attainment (P < .001).ConclusionsCompliance with diabetic foot screening and ulcer risk stratification in patients with type 2 diabetes in Primary Care was poor.     

Eolimna martinii n. gen., n. sp. (Bacillariophyceae) aus dem Unter-Oligozän von Sieblos/Rhön im Vergleich mit ähnlichen rezenten Taxa

The laminated sediments of the Lower Oligocene ‘Sieblos-Schichten’ (dysodile and kieselgur-sediments) contain many individuals of a naviculoid diatom species. Formerly this group of diatoms would have been classified without doubt as Navicula (section ‘Minusculae’). After splitting this extremely heterogeneous genus in Navicula sensu stricto and some other homogeneous genera, the pattern of structures of this fossil species does not correspond to any established genus. For that reason this form will be described as the generotype of a new genus Eolimna. Furthermore it became evident that some Recent species (assigned to Navicula) show the same pattern of structures as the new genus Eolimna (generotype: E. martinii) which represents one of the first naviculoid diatoms of limnic origin. The essential criteria of this genus are: comparatively small cells with narrow girdle; simple alveolated rib system; areolae with a hymen in approximately medium position between relatively large sized foramina outside and inside of the valve; a single row of more or less irregular arranged areolae in close position to each other, on one or several of the copulae. The differences to supposed related genera are discussed.     

Soporte nutricional con nutrición parenteral. Evolución y complicaciones asociadas

IntroductionParenteral nutrition (PN) is an integral part of medical management of patients who do not have a functioning or accessible gastrointestinal tract. This paper discusses the clinical characteristics of patients receiving PN in a 420-bed hospital from 2009 to 2011. In addition, nutritional parameters were assessed at the start and end of PN and associated complications were analyzed.Material and methodsretrospective, observational study of PN episodes in adults conducted at the Nutrition Unit of Hospital Universitario de Guadalajara. Variables collected included epidemiological and clinical data, number and type of routes used, anthropometric data, analytical data, number of days on PN, reason for withdrawal, caloric provision, prevalence of phlebitis, metabolic complications (hypertriglyceridemia, abnormal liver function tests, hyperglycemia, and refeeding syndrome), and prevalence of bacteremia associated with central venous catheter (BAC).ResultsThere were 312 episodes of PN. The immediate indication was postoperative ileus in 53.8% of the episodes. There was a statistically significant improvement in all analytical parameters assessed (albumin, prealbumin, retinol binding protein, transferrin, cholesterol, and lymphocytes). Caloric provision (kcal per kg) was 25.1 ± 6.6. No metabolic complication occurred in 16.3% of the episodes, and hyperglycemia was the most common complication (79.8%). There were 10 cases of phlebitis (32.2%) and 30 episodes of BAC (8.7%). Bacteriemia rate was 8.1 per 1000 days of PN.DiscussionAlthough PN is an effective nutritional support technique, it is associated with complications of varying severity. Use of PN should therefore comply with the instructions accepted in the main clinical practice guidelines and requires careful monitoring by experienced professionals.     

Formación de cuidadores en un programa de estimulación cognitiva: efectos diferenciales según el tipo de cuidador

Background and objectivesThe ageing population and the increasing dependency associated with it, makes the caregiver a highly relevant figure nowadays. The present study analyzes the socio-demographic differences between family and professional caregivers and their satisfaction and implication in a training program for caregivers.MethodsThe sample consisted of 59 caregivers of older people (37 were family caregivers and 22 professional caregivers) which received and implemented a caregivers training program in their daily care functions. These caregivers were trained in communication skills and cognitive stimulation strategies so they could use them in their daily care activities with the older adults under their care during a period of 3 months. All the participants were assessed with a socio-demographic questionnaire, 2 questionnaires to analyze their satisfaction with their work and the training received and one questionnaire to analyze their ability to detect and react to memory and behavior problems in the older adults they attended.ResultsThe results showed socio-demographic differences, improvements in satisfaction in family caregivers and a greater commitment in their daily work after the treatment in both groups although these effects could be due to different reasons.ConclusionsThe research shows the benefits of carrying out training programs for caregivers as they significantly increase the quality and satisfaction with caregiving. The study also displays the need to adjust such programs taking into account that the socio-demographic characteristics and training needs are different depending on whether de caregiver is a family member or a professional.