The state of the art in beyond 5G distributed massive multiple-input multiple-output communication system solutions.

Beyond fifth generation (5G) communication systems aim towards data rates in the tera bits per second range, with improved and flexible coverage options, introducing many new technological challenges in the fields of network architecture, signal pro- cessing, and radio frequency front-ends. One option is to move towards cell-free, or distributed massive Multiple-Input Multiple-Output (MIMO) network architectures and highly integrated front-end solutions. This paper presents an outlook on be- yond 5G distributed massive MIMO communication systems, the signal processing, characterisation and simulation challenges, and an overview of the state of the art in millimetre wave antennas and electronics.

[Legally regulated teleradiology: implementation of data protection legal requirements]. / Gesetzlich geregelte Teleradiologie: Umsetzung der datenschutzrechlichen Anforderungen.

With the introduction of the Radiation Protection Act (StrlSchG) and the Radiation Protection Regulations (StrlSchV), which "replaced" the Roentgen Regulations (RöV) on 31 December 2018, there has been little change regarding teleradiology-specific requirements. Nevertheless, the data protection requirements of the General Data Protection Regulations (GDPR) also apply to teleradiology. Primarily, any processing of healthcare data is prohibited if there is no legal basis for permission. Thereafter, the established principles laid down in Art. 5 GDPR must be demonstrably fulfilled, patients must be informed and the security of the data must be guaranteed, etc.It is fundamentally necessary to clarify on what legal basis the cooperation between the treating hospital and the teleradiologist takes place: is it an independent treatment by the teleradiologist alone or is it more a joint processing in the sense of Art. 26 GDPR? If teleradiology is using new technologies, e.g. the distribution via a cloud solution, a data protection impact assessment may have to be carried out.Even though many requirements of the GDPR are already addressed by the teleradiological requirements alone and they are already implemented in an approved teleradiology, there are still some points that should be looked at more closely.

[Innovative teleradiology network: concept and experience report]. / Innovativer Teleradiologieverbund: Konzept und Erfahrungsbericht.

(DICOM E-MAIL provides a standardized way for exchanging DICOM objects (Digital Imaging and Communications in Medicine) and further relevant patient data for the treatment context reliably and securely via encrypted e-mails. The current version of the DICOM E-MAIL standard recommendations of the"Deutsche Röntgengesellschaft" (DRG, German Röntgen Society) defines for the first time options for setting up a special directory service for the provision and distribution of communication data of all participants in a network. By using such"telephone books", networks of any size can be operated independent of the provider. Compared to a Cross-Enterprise Document Sharing (XDS) scenario, the required infrastructure is considerably less complex and quicker to realize. Critical success factors are, in addition to the technology and an effective support, that the participants themselves contribute to the further development of the network and in this way, the network approach can be practiced.

Valproate release from polycaprolactone implants prepared by 3D-bioplotting.

In this study we examined the release kinetics of valproate from polycaprolactone (PCL) implants constructed for local antiepileptic therapy. The PCL implants were produced with a novel 3D-Bioplotting technology. Release kinetics were determined by superfusion of these implants. Valproate was measured in the superfusate fractions with high pressure liquid chromatography (HPLC). The HPLC measurements were linear over a concentration range of 10-500 microg/mL for valproate and the limit of quantification was found to be 9 microg/mL. The HPLC method used is simple, accurate and sensitive. Within the first day, valproate (10% w/w)-PCL implants released already 77% of the maximum possible liberated amount whereas (5% w/w)-PCL implants released only 53%. After four days, 88% of valproate was released from (10% w/w)-PCL implants and 94% valproate from (5% w/w)-PCL implants. When valproate was ground before the 3D-Bioplotting process, only 63% from (10% w/w)-PCL implants was released within the first day. This released amount of ground valproate was significantly lower compared to that which was not ground from the (10% w/w)-PCL implants. After three days of superfusion a total amount of 89% of ground valproate within the implants was released, corresponding to 88% of non-ground valproate after four days. The fast releasing PCL implants can be used to study acute effects of locally applied valproate on epileptogenesis in vivo after initiation of an epileptic focus in an animal model. The corresponding biocompatibility may also be analysed.

Effects of antiepileptic drugs on GABA release from rat and human neocortical synaptosomes.

In epilepsy, allegedly, a neurotransmitter imbalance between the inhibitory GABA and the excitatory glutamate prevails. Therefore, some antiepileptic drugs (AEDs) are thought to increase GABA release. Because little is known about corresponding presynaptic effects of AEDs in the human brain, this study investigated the effects of carbamazepine, lamotrigine, phenytoin, gabapentin, pregabalin, levetiracetam, and valproate on (3)H-GABA release from human neocortical synaptosomes preincubated with (3)H-GABA. To obtain information on possible species differences, rat neocortical synaptosomes were investigated concomitantly. Release was evoked by either veratridine (1, 3.2, or 10 µM), which prevents activated voltage-dependent Na(+) channels from closing, or elevation of extracellular [K(+)] from 3 to 15 mM. The exocytosis inhibitor tetanus toxin (TeT) or withdrawal of buffer Ca(2+) (Ca (e) (2+) ) reduced K(+)-evoked release in both species, while blockade of Na(+) channels with tetrodotoxin had no effect. K(+)-evoked release was characterized as predominant, Ca(2+)-dependent and Na(+)-independent, exocytosis. Carbamazepine and phenytoin in the rat and carbamazepine, phenytoin, lamotrigine, and valproate in human tissue reduced K(+)-evoked (3)H-GABA release. With respect to veratridine-evoked release, Ca (e) (2+) withdrawal did not reduce release in the rat; it even increased the release in human tissue. TeT was slightly inhibitory in the rat. Blockade of GABA transport diminished veratridine-evoked (3)H-GABA release in either species. This release was characterized as mediated mainly by transporter reversal. Carbamazepine, lamotrigine, and phenytoin in rat tissue and carbamazepine and phenytoin in human decreased veratridine-induced (3)H-GABA release. Interestingly, no AED increased (3)H-GABA release. The reduction by AEDs of veratridine-evoked release was more intense than that of K(+)-evoked release. In conclusion, reduction of GABA release by AEDs may be the actual objective in a pathologically altered neuronal network where GABA acts in a depolarizing fashion.

Effects of antiepileptic drugs on glutamate release from rat and human neocortical synaptosomes.

Aim of this study was to learn whether the antiepileptic drugs (AEDs) carbamazepine, lamotrigine, phenytoin, gabapentin, pregabalin, levetiracetam, and valproate (all at 100 µM) presynaptically influence the neurotransmission of the excitatory transmitter glutamate. The effects of these frequently used AEDs were examined on ³H-glutamate release from superfused synaptosomes of both rat and human neocortex. Release was evoked by elevation of buffer [K(+)] from 3 to 15 mM or by the Na(+) channel activator veratridine (1, 3.2, and 10 µM). Buffer [K(+)] elevation induced ³H-glutamate exocytosis, which was Ca(²+)-, but not Na(+)-, dependent and which was accompanied only in human tissue by release through transporter reversal. In rat tissue, release was diminished by the Na(+) channel inhibitors carbamazepine, lamotrigine, and phenytoin, which therefore may also affect presynaptic Ca(²+) channels. Interestingly, levetiracetam increased ³H-glutamate release. In contrast, the tested AEDs did not affect K(+)-evoked ³H-glutamate release in human tissue, neither when the transporters were operative nor when exocytosis was isolated by transporter blockade. Veratridine-evoked ³H-glutamate release was a Na(+)-dependent transmitter efflux through reversed transporters in both species which in human synaptosomes was accompanied by exocytosis. The latter depended on external Ca(²+). Carbamazepine, lamotrigine, and phenytoin reduced this release from both rat and human tissue. There is an obvious species difference in the effects of carbamazepine, lamotrigine, and phenytoin on K(+)-evoked ³H-glutamate release while their inhibitory effects on veratridine-evoked release were similar. Thus, the depression of ³H-glutamate release by carbamazepine, lamotrigine, and phenytoin may be due to inhibited synaptosomal Na(+) or Ca(²+) influx.

Salivary alpha-amylase stability, diurnal profile and lack of response to the cold hand test in young women.

Salivary cortisol measurement has proved useful for the non-invasive study of the hypothalamic-pituitary-adrenocortical axis, and salivary alpha-amylase has been suggested as a comparable marker for the sympathetic system. Despite some studies showing an increase in salivary alpha-amylase after challenges that stimulate the sympathetic nervous system, questions remain about interpretation. The aims of this study were to explore the stability of salivary alpha-amylase, its diurnal profile, response to the cold hand test, and correlation with cortisol. Salivary alpha-amylase was stable following 5 days at room temperature, and five freeze-thaw cycles. Its diurnal profile was opposite to that of cortisol. There was no salivary alpha-amylase response to the cold hand stress test, in the morning (11am) or afternoon (3pm), unlike cortisol which showed a response in the afternoon in the same samples. There was no correlation between salivary alpha-amylase and cortisol at any time. In conclusion, salivary alpha-amylase is stable to a range of conditions. Its diurnal pattern is compatible with sympathetic stimulation. Lack of response to the cold hand test suggests that secretion of salivary alpha-amylase is controlled by mechanisms more complex than sympathetic regulation alone.

Nitrate and nitrite concentrations in rabbit saliva Comparison with rat saliva.

The purpose of this work was to investigate the interest of rabbits for studying pharmacology and toxicology of dietary nitrate. Twenty-one females were given 1, 300 and 600mg/l nitrate in drinking water for 11 weeks. Saliva and blood were analysed for nitrate/nitrite. There is a linear relationship between the amounts of nitrate ingested and amount of nitrate in saliva, contrary to what is observed in rats. However, salivary nitrite concentrations remain low, and nitrate reductase activity in the oral cavity of the rabbit seems very weak.

The HPA axis and perinatal depression: a hypothesis.

Episodes of depression and anxiety are as common during pregnancy as postpartum. Some start in pregnancy and resolve postpartum, others are triggered by parturition and some are maintained throughout. In order to determine any biological basis it is important to delineate these different subtypes. During pregnancy, as well as the rise in plasma oestrogen and progesterone there is a very large increase in plasma corticotropin releasing hormone (CRH), and an increase in cortisol. The latter reaches levels found in Cushing's syndrome and major melancholic depression. Levels of all these hormones drop rapidly on parturition.We here suggest that the symptoms of antenatal and postnatal depression may be different, and linked in part with differences in the function of the hypothalamic pituitary adrenal (HPA) axis. There are two subtypes of major depression, melancholic and atypical, with some differences in symptom profile, and these subtypes are associated with opposite changes in the HPA axis. Antenatal depression may be more melancholic and associated with the raised cortisol of pregnancy, whereas postnatal depression may be more atypical, triggered by cortisol withdrawal and associated with reduced cortisol levels. There is evidence that after delivery some women experience mild bipolar II depression, and others experience post traumatic stress disorder. Both of these are associated with atypical depression. It may also be that some women are genetically predisposed to depression of the melancholic type and some to depression of the atypical type. These women may be more or less vulnerable to depression at the different stages of the perinatal period.

[E-Learning in radiology; the practical use of the content management system ILIAS]. / E-Learning in der Radiologie -- praktischer Einsatz des Content-Management-Systems Ilias.

PURPOSE: Due to the possibility of using different kinds of visualization, e-learning has the advantage of allowing individualized learning. A check should be performed to determine whether the use of the web-based content management system ILIAS simplifies the writing and production of electronic learning modules in radiology. MATERIALS AND METHODS: Internet-based e-learning provides access to existing learning modules regardless of time and location, since fast Internet connections are readily available. RESULTS: Web Content Management Systems (WCMS) are suitable platforms for imparting radiology-related information (visual abilities like the recognition of patterns as well as interdisciplinary specialized knowledge). The open source product ILIAS is a free WCMS. It is used by many universities and is accepted by both students and lecturers. Its modular and object-oriented software architecture makes it easy to adapt and enlarge the platform. The employment of e-learning standards such as LOM and SCORM within ILIAS makes it possible to reuse contents, even if the platform has to be changed. CONCLUSION: ILIAS renders it possible to provide students with texts, images, or files of any other kind within a learning context which is defined by the lecturer. Students can check their acquired knowledge via online testing and receive direct performance feedback. The significant interest that students have shown in ILIAS proves that e-learning can be a useful addition to conventional learning methods.

The Public-Key-Infrastructure of the Radiological Society of Germany.

Pretty Good Privacy (PGP) encoding is based on the Public-Key-Procedure and permits the safe transmission of medical data. Furthermore it allows the use of an electronic signature provided that keys used belong to the key owner and that the key owner's identity is guaranteed by a trusted third party. Under the auspices of the Radiological Society of Germany (Deutsche Röntgengesellschaft, DRG) its IT-Working Group (Arbeitsgemeinschaft für Informationstechnik, @GIT) built up an appropriate Certification Authority including the required Public-Key-Infrastructure. These @GIT certified PGP keys allow the legal use of telemedicine in Germany. Digital signatures based to those certified keys correspond to the advanced signature according to the German Signature Law.

Standardization of teleradiology using Dicom e-mail: recommendations of the German Radiology Society.

Until recently there has been no standard for an interoperable and manufacturer-independent protocol for secure teleradiology connections. This was one of the main reasons for the limited use of teleradiology in Germany. Various teleradiology solutions have been developed in the past, but the vast majority have not been interoperable. Therefore an ad hoc teleradiology connection was impossible even between partners who were already equipped with teleradiology workstations. Based on the evaluation of vendor-independent protocols in recent years the IT Working Group (AGIT) of the German Radiology Society set up an initiative to standardize basic teleradiology. An e-mail based solution using the Dicom standard for e-mail attachments with additional encryption according to the OpenPGP standard was found to be the common denominator. This protocol is easy to implement and safe for personalized patient data and fulfills the legal requirements for teleradiology in Germany and other countries. The first version of the recommendation was presented at the 85th German Radiology Convention in 2004. Eight commercial and three open-source implementations of the protocol are currently available; the protocol is in daily use in over 50 hospitals and institutions.

[Teleradiology according to the x-ray ordinance--exemplary application of the open source software SecTelMed]. / Teleradiologie nach Röntgenverordnung - beispielhafte Anwendung der Open-Source-Software SecTelMed.

PURPOSE: Establishing a teleradiology connection according to the Rontgenverordnung (RoV) between a peripheral hospital and a university clinic will contribute to improve the radiological emergency treatment on weekends, holidays and at night. It will also better the medical care for patients and help to lower the costs. MATERIALS AND METHODS: By using the open source software SecTelMed, the radiological picture is transferred via an internet-linked SSH communication server. The integration of the teleradiological data transfer into the actual workflow is attained by using the already existing PACS infrastructure. While its installation is still under construction, it is actually employed for transferring a patient's preliminary investigations and obtaining second opinions. RESULTS: The project proves a reliable and affordable teleradiology according with RoV by using open source software. The applied infrastructure ensures an unproblematical teleradiological treatment as well as a safe picture transfer for medical consulting (second opinion) even for large CT examinations of 1,000 pictures and more. CONCLUSION: The implementation of the technical requirements on teleradiology according with the Rontgenverordnung can be reliably attained by applying the open source software SecTelMed.

[Teleradiology with DICOM e-mail: recommendations of @GIT]. / Teleradiologie mit DICOM E-mail: Empfehlungen der @GIT.

E-mail is ideal for ad-hoc connections in teleradiology. The DICOM standard offers the possibility to append DICOM data types as a MIME attachment to any e-mail, thus ensuring the transmission of the original DICOM data. Nevertheless, there are additional requirements (e.g. protection of data privacy) which must be obeyed. Because of the lack of given standards which would grant interoperability as well as manufacturer independence, teleradiology has not been established in Germany until today. Therefore, the IT-Team (Arbeitsgemeinschaft fur Informationstechnologie, @GIT) of the Radiological Society of Germany (Deutsche Rontgengesellschaft, DRG) set up an initiative to standardise telemedicine by using e-mail. Its members agreed that an e-mail-based variant would be the most practicable way to a communication solution -- as easy to implement as to use. In their opinion, e-mail represents the smallest common denominator for a safe data interchange that would fulfill the legal advantages for telemedicine in Germany.

Liver and kidney concentrations of vanadium in oiled seabirds after the Erika wreck.

Vanadium was measured by atomic absorption spectrophotometry in the liver and kidney of several oiled seabirds that were stranded on the French Atlantic coasts after the Erika wreck and died in wildlife care Centers. Estimated averages were 30 to 77 ng g(-1) wet weight (ww) in the liver and 52 to 72 ng g(-1) wet weight in the kidney. These concentrations were not higher in oiled birds than in dead birds found later, without visible traces of petroleum on beaches not affected by the Erika pollution. Vanadium hepatic and renal concentrations do not seem to be appropriate biomarkers for recent exposure to fuel in seabirds.

Postnatal depression across countries and cultures: a qualitative study.

BACKGROUND: Postnatal depression seems to be a universal condition with similar rates in different countries. However, anthropologists question the cross-cultural equivalence of depression, particularly at a life stage so influenced by cultural factors. AIMS: To develop a qualitative method to explore whether postnatal depression is universally recognised, attributed and described and to enquire into people's perceptions of remedies and services for morbid states of unhappiness within the context of local services. METHOD: The study took place in 15 centres in 11 countries and drew on three groups of informants: focus groups with new mothers, interviews with fathers and grandmothers, and interviews with health professionals. Textual analysis of these three groups was conducted separately in each centre and emergent themes compared across centres. RESULTS: All centres described morbid unhappiness after childbirth comparable to postnatal depression but not all saw this as an illness remediable by health interventions. CONCLUSIONS: Although the findings of this study support the universality of a morbid state of unhappiness following childbirth, they also support concerns about the cross-cultural equivalence of postnatal depression as an illness requiring the intervention of health professionals; this has implications for future research.

Adaptation of the structured clinical interview for DSM-IV disorders for assessing depression in women during pregnancy and post-partum across countries and cultures.

BACKGROUND: To date, no study has used standardised diagnostic assessment procedures to determine whether rates of perinatal depression vary across cultures. AIMS: To adapt the Structured Clinical Interview for DSM-IV Disorders (SCID) for assessing depression and other non-psychotic psychiatric illness perinatally and to pilot the instrument in different centres and cultures. METHOD: Assessments using the adapted SCID and the Edinburgh Postnatal Depression Scale were conducted during the third trimester of pregnancy and at 6 months postpartum with 296 women from ten sites in eight countries. Point prevalence rates during pregnancy and the postnatal period and adjusted 6-month period prevalence rates were computed for caseness, depression and major depression. RESULTS: The third trimester and 6-month point prevalence rates for perinatal depression were 6.9% and 8.0%, respectively. Postnatal 6-month period prevalence rates for perinatal depression ranged from 2.1% to 31.6% across centres and there were significant differences in these rates between centres. CONCLUSIONS: Study findings suggest that the SCID was successfully adapted for this context. Further research on determinants of differences in prevalence of depression across cultures is needed.

Contextual Assessment of the Maternity Experience: development of an instrument for cross-cultural research.

BACKGROUND: There is evidence that stressors may trigger the onset of a depressive episode in vulnerable women. A new UK interview measure, the Contextual Assessment of the Maternity Experience (CAME), was designed to assess major risk factors for emotional disturbances, especially depression, during pregnancy and post-partum. AIMS: With in the context of a cross-cultural study, to establish the usefulness of the CAME, and to test expected associations of the measure with characteristics of the social context and with major or minor depression. METHOD: The CAME was administered antenatally and postnatally in ten study sites, respectively to 296 and 249 women. Affective disorder throughout pregnancy and up to 6 months postnatally was assessed by means of the Structured Clinical Interview for DSM-IVAxis I Disorders. RESULTS: Adversity, poor relationship with either a partner or a confidant, and negative feelings about the pregnancy all predicted onset of depression during the perinatal period. CONCLUSIONS: The CAME was able to assess major domains relevant to the psychosocial context of the maternity experience in different cultures. Overall, the instrument showed acceptable psychometric properties in its first use in different cultural settings.

Maternal attachment style and depression associated with childbirth: preliminary results from a European and US cross-cultural study.

BACKGROUND: Insecure attachment style relates to major depression in women, but its relationship to depression associated with childbirth is largely unknown. A new UK-designed measure, the Attachment Style Interview (ASI), has potential for cross-cultural use as a risk marker for maternal disorder. AIMS: To establish there liability of the ASI across centres, its stability over a 9-month period, and its associations with social context and major or minor depression. METHOD: The ASI was used by nine centres antenatally on 204 women, with 174 followed up 6 months postnatally. Interrater reliability was tested and the ASI was repeated on a subset of 96 women. Affective disorder was assessed by means of the Structured Clinical Interview for DSM-IV. RESULTS: Satisfactory interrater reliability was achieved with relatively high stability rates at follow-up. Insecure attachment related to lower social class position and more negative social context. Specific associations of avoidant attachment style (angry-dismissive or withdrawn) with antenatal disorder, and anxious style (enmeshed or fearful) with postnatal disorder were found. CONCLUSIONS: The ASI can be used reliably in European and US centres as a measure for risk associated with childbirth. Its use will contribute to theoretically under pinned preventive action for disorders associated with childbirth.

Measurement of mother-infant interactions and the home environment in a European setting: preliminary results from a cross-cultural study.

BACKGROUND: Infant development is adversely affected in the context of postnatal depression. This relationship may be mediated by both the nature of early mother-infant interactions and the quality of the home environment. AIM: To establish the usefulness of the Global Ratings Scales of Mother-Infant Interaction and the Infant-Toddler version of the Home Observation for the Measurement of the Environment (IT-HOME), and to test expected associations of the measures with characteristics of the social context and with major or minor depression. METHOD: Both assessments were administered postnatally in four European centres; 144 mothers were assessed with the Global Ratings Scales and 114 with the IT-HOME. Affective disorder was assessed by means of the Structured Clinical Interview for DSM-IV Disorders. RESULTS: Analyses of mother-infant interaction indicated no main effect for depression but maternal sensitivity to infant behaviour was associated with better infant communication, especially for women who were not depressed. Poor overall emotional support also reduced sensitivity scores. Poor support was also related to poorer IT-HOME scores, but there was no effect of depression. CONCLUSIONS: The Global Ratings Scales were effectively applied but there was less evidence of the usefulness of the IT-HOME.