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Background Glucokinase-maturity-onset diabetes of the young (GCK-MODY) is a form of diabetes caused by heterozygous inactivating mutations in the GCK gene. Affected individuals maintain their fasting glucose levels at a higher set point (5.4-8.3 mmol/l) than the general population. Hyperglycaemia in women with Type 1 or Type 2 diabetes is known to confer increased risk of fetal congenital abnormalities. The association between GCK-MODY and congenital abnormalities, however, remains uncertain. Case report A 35-year-old woman in her third pregnancy was diagnosed with gestational diabetes at 13 weeks' gestation (fasting blood glucose 6.0 mmol/L, 1-h blood glucose 9.2 mmol/l, 2-h blood glucose 7.3 mmol/l). The morphology scan at 19+2 weeks' gestation showed a Type III sacral agenesis. The woman elected to terminate the pregnancy. Her postpartum oral glucose tolerance test was suggestive of GCK-MODY (fasting blood glucose 7.4 mmol/l, 1-h blood glucose 9.3 mmol/l, 2-h blood glucose 7.3 mmol/l). Mutation analysis of the GCK gene identified a novel heterozygous GCK missense mutation, p.V199M, classified as likely pathogenic, providing molecular confirmation of the suspected GCK-MODY diagnosis. Discussion Sacral agenesis is a rare form of sacral abnormality affecting 0.005% to 0.1% of pregnancies. It is a subtype of the caudal regression sequence, a cardinal feature of diabetic embryopathy. This case raises the question as to whether hyperglycaemia in GCK-MODY may increase the risk of fetal caudal regression syndrome as reported in women with pre-existing diabetes mellitus. Improved diagnostic rates of GCK-MODY, and MODY registers that include pregnancy outcomes, are important to further elucidate risk of congenital abnormalities in GCK-MODY.

This is a description of similar prenatal ultrasound findings in five cases of fetal Costello syndrome from 3 countries. We suggest that Costello syndrome (CS) may be recognizable prenatally, is more prevalent in utero than previously described, and that cases diagnosed prenatally have a more severe phenotype and a high risk of intrauterine death compared with cases diagnosed postnatally. This article is protected by copyright. All rights reserved.

Two siblings, from a consanguineous Iraqi family, were investigated to identify the underlying genetic cause of their high myopia, esotropia, vitreous changes and cataract. Subsequent investigation identified low molecular weight proteinuria as part of their syndrome. Exome sequencing of one of the probands revealed a new non-synonymous variant in the LRP2 gene. Sanger sequencing confirmed the mutation and segregation in the family. No mutation was identified in COL9A1/2, COL11A1/2, or COL2A1 genes. The variant (c.11483A>G; p.Asp3828Gly) is predicted to be damaging and is conserved among vertebrate species. Mutations in LRP2 have been shown to cause the Donnai-Barrow syndrome (DBS) or facio-oculo-acoustico-renal (FOAR) syndrome, a syndrome associated with facial dysmorphism, ocular anomalies, sensorineural hearing loss, low molecular weight proteinuria, and diaphragmatic hernia and absent corpus callosum, although there is variability in the expression of some features. This family shows a milder phenotype with a predominant eye phenotype similar to the Stickler syndrome and only a few features of the DBS, including microglobulinuria. The presence of microglobulinuria was only detected after molecular results were known. In conclusion, with the identification of a new mutation in LRP2 associated with a predominant eye phenotype similar to the Stickler syndrome, we have broadened the phenotypic spectrum of LRP2 mutations.

The quest for electrically pumped organic laser is now conducted in several places around the globe. In this paper we outline our approach to this long-term project and aim to describe both encouraging and challenging (discouraging?) results. We describe experimental results using polymers, polymer blends and triplet emitters in an LED configuration using either CW or pulsed mode of operation. We also describe results of modeling such structures with the aim of being able to design electrical and optical characteristics of future laser structures. Finally we describe an approach to modify material parameters so as to provide a range of building blocks for optoelectronic devices.

We present a systematic experimental and theoretical study of physical mechanisms governing the operation of polymer light-emitting diodes. We show that through self-consistent modeling we can address both charge transport and exciton generation. Electron and hole mobility in several polymers has been characterized experimentally. Characterization of excitons and especially of triplet-excitons is achieved through use of a triplet-emitting molecule.

We present a range of measurement techniques (time-resolved and CW) of various polymers in a variety of LED configurations. Using time-resolved pulsed electrical excitation, we are able to provide direct evidence for the motion of both types of carriers. We use pulses to probe the decay of carriers on time scales from nanosecond to millisecond. We address the issue of pulsed vs. CW properties and find that the functional form (power law) of the current–voltage curves is affected by the measurement technique; we also discuss a method to produce “intrinsic” curves. We introduce the method of using double electrical pulses to probe the dynamics of the stored charges after the application of a pulse.

We present a numerical model which is capable of time-resolving the electron, hole, and exciton density distribution. To simulate a close to real device, we include effects due to the metal electrode as quenching, modified radiation rate, and enhanced output coupling. Using this model, we provide a framework for the experimental extraction of mobility values from transient light response that accounts for the diffusion-induced broadening of the carrier front.

Emission patterns from the films of polyfluorene derivative on silica substrates are found to show light emission at grazing angles to the substrate. This light is found to be polarised and to have a narrowed emission, as well as enhanced intensity with respect to the light collected in the forward direction. Both the wavelengths of the peaks and their polarisation (s or p) are thickness-dependent. The peak's wavelength positions are used to characterise the spectrum of the refractive indices of the film both in and out of plane. The relative intensity of s- to p-polarised peaks serves as an independent indication of the dipole orientation. The deduced dipole in-plane alignment ratio (88%) and the magnitude of the birefringence (Δ n =0.2 at λ =600 nm) suggest that the main chains of this polymer lie preferentially in plane of the film. These findings seem to be consistent with the rod structure of the polymer studied.

It has been shown that conjugated polymers possess the two basic requirements for electrically pumped lasers: (1) they can support optically-pumped lasing, and (2) they can support current densities of kA/cm2. However, electrically pumped lasing has not been realised yet. The above-mentioned prerequisites are sufficient when traditional III–V lasers are concerned. However, conjugated polymers are in many ways different and hence require a slightly modified emphasis. We will discuss materials related issues such as charge-induced absorption, charge-mobility, exciton generation, as well as device-related properties such as architecture and driving scheme.

We present theoretical and experimental analysis of conjugated polymer-based devices. We show that by combining a detailed optical and electrical theoretical model with a variety of experimental techniques it becomes possible to access many of the internal processes.

The method of applying two consecutive voltage pulses is presented as a method to study the dynamics of injected charges in the “off-state,” i.e., after the removal of the applied voltage pulse. Pulses of different widths are used to selectively probe the dynamics of holes and electrons. The use of multiple (>2) pulses is also described as an additional carrier monitoring technique.

We present experimental techniques to analyze the electroluminescence (EL) of polymer light-emitting diodes following the removal of an applied voltage pulse. We explain the fast modulation of the EL intensity at turn-off in terms of the sudden reduction of the Langevin recombination rate, and extract the time evolution the device’s internal electric field at the recombination zone during the application of a voltage pulse. The results are compared to, and found to be consistent with, those of simple numerical modeling. The subsequent long-lived EL tail is analyzed to give the time evolution of the carrier distributions at the recombination zone once the voltage pulse has been removed.

We present a theoretical and experimental study of electrical pulsed excitation in polymer light-emitting diodes (LEDs). We find that the low mobility results in a relatively high charge density within an electrically pumped structure. The broad spectrum of the charge-induced absorption and its overlap with the ground-state absorption pose a significant barrier for achieving net gain and lasing. We suggest an approach that might circumvent this problem using suitable emitters and an appropriate driving scheme. We also suggest methods for ultrafast modulation of LEDs as well as direct determination of the space charge within the recombination zone.

Detailed experimental and theoretical analysis of the pulsed excitation of polymer light emitting diodes is presented. We find a set of universal transient features for different device configurations which can be reproduced using our phenomenological numerical model. We find that the temporal evolution of the electroluminescence can be characterised by five main features: i) a delay followed by; ii) fast initial rise at turn-on followed by; iii) a slow rise (slower by at least one order of magnitude); iv) fast modulation (

We have studied various two layer polymer light emitting diodes (LEDs) by applying a wide range of voltage pulses (100ns - 1 micosecond, 10–100V). We find that it is possible to move the recombination zone about the polymer/polymer heterojunction as a function of the applied voltage, and that the colour change depends on the charge injection, relative carrier mobilities and their field dependence. Preliminary simulation runs for these devices are also presented. Two current decay components (fast 100ns and slow 1ms) have been observed in the current response of a device after the application of microsecond pulses, which we attribute to the presence of mobile and immobile carriers. IVL and efficiency data presented show that LEDs perform better in pulsed than in d.c. operation. We also report peak brightnesses in LEDs in excess of 10 million Cd/m 2 at current densities of 500A/cm 2 under the application of 1MV/cm electric field.

We present detailed experimental and theoretical analysis for both constant-wave and pulsed excitation for a variety of real bilayer organic light-emitting diodes (LEDs). We find from experiment and simulation that the recombination zone may be moved about the polymer-polymer heterojunction as a function of the applied voltage. We suggest a method for spectrally resolving the emission of both polymers of a bilayer LED as a function of time, and show that these results are in good agreement with time-dependent simulation results. The simulation model takes into account both the discontinuities in energy levels and mobilities across the polymer-polymer heterojunction.

The terms fissure and sulcus as they are classically defined are: a fissure separates one lobe from another, while a sulcus is within a lobe and delimits gyri.

During the development of the embryo, the first vein to appear in the posterior fossa is, according to PADGET (1956), the primitive ventral metencephalic vein since, at this stage, the cerebellar hemisphere is merely represented by a cerebellar plate. This ventral metencephalic vein, homologous to the trigeminal vein of lower vertebrates, will eventually become the petrosal vein. The proximal end of the ventral metencephalic vein becomes incorporated into the petrous crest to form the superior petrosal sinus. The primitive ventral myelencephalic vein, also called the vagal vein (PADGET, 1956), anastomoses superiorly with the ventral metencephalic vein and drains the medulla oblongata. The inferior petrosal sinus is derived from the proximal end of the ventral myelencephalic vein.

The basal cerebral vein described by ROSENTHAL in 1824 has been the subject of many investigations.

The aqueduct of Sylvius represents the communication between the third and fourth ventricles. It is 15 to 18 mm long and 1 to 2 mm in diameter. Its shape is like the neck of a swan. Posteriorly, its relations are, from superiorly to inferiorly, the posterior commissure, the superior and inferior colliculi and the anterior medullary velum. Its floor is the midbrain, and contains the nuclei of the third and fourth cranial nerves (Fig. 153).

The vertebral arteries, basilar trunk and their branches provide the vascular supply to the brainstem and cerebellum. The anatomy of these arteries has been studied by STOPFORD (1917), FOIX and HILLEMAND (1925) and LAZORTHES, POULHES and ESPAGNO (1950).

The deep cerebral venous system may be said to consists of the two internal cerebral veins and their tributaries—the subependymal, deep medullary, superior striate and choroidal veins. The basal cerebral vein, sometimes included in the deep venous system, is described elsewhere (Part 1, Chap. 4, p. 128).

1. Cerebral Hemisphere.- 1. Fissures and Sulci (G. S.).- I. Anatomic Study of the Fissures and Sulci of the External Surface of the Cerebral Hemisphere.- 1. Principal or Interlobar Fissures.- 2. Sulci of the External Surface.- a) Sulci of the Frontal Lobe.- b) Sulci of the Parietal Lobe.- c) Sulci of the Occipital Lobe.- d) Sulci of the Temporal Lobe.- II. Anatomic Study of the Fissures and Sulci of the Internal Surface of the Cerebral Hemisphere.- 1. Fissures of the Internal Surface.- 2. Sulci of the Internal Surface.- III. Anatomic Study of the Fissures and Sulci of the Inferior Surface of the Cerebral Hemisphere.- 1. Fissure of the Inferior Surface-Sylvian Fissure.- 2. Sulci of the Inferior Surface.- a) Sulci of the Orbital Surface of the Frontal Lobe.- b) Sulci of the Inferior Surface of the Temporal and Occipital Lobes.- IV. Radiologic Study of Fissures and Sulci.- 2. Lateral Ventricles (G. S.).- I. Anatomic Study of the Lateral Ventricles.- 1. Frontal Horn of the Lateral Ventricle.- 2. Body of the Lateral Ventricle.- 3. Atrium of the Lateral Ventricle.- 4. Occipital Horn of the Lateral Ventricle.- 5. Temporal Horn of the Lateral Ventricle.- II. Radiologic Study of the Lateral Ventricles.- 1. Frontal Horn of the Lateral Ventricle.- 2. Body of the Lateral Ventricle.- 3. Atrium of the Lateral Ventricle.- 4. Occipital Horn of the Lateral Ventricle.- 5. Temporal Horn of the Lateral Ventricle.- 3. Cortical Arteries (G. S.).- A. Anterior Cerebral Artery.- I. Anatomic Study of the Anterior Cerebral Artery.- Branches of the Anterior Cerebral Artery.- a) Branch to the Orbital Surface of the Frontal Lobe.- b) Branches to the Internal Surface of the Frontal Lobe.- c) Branch to the Paracentral Lobule.- d) Branches to the Internal Aspect of the Parietal Lobe.- e) Branches to the Corpus Callosum.- II. Radiologic Study of the Anterior Cerebral Artery.- B. Middle Cerebral Artery.- I. Anatomic Study of the Middle Cerebral Artery.- 1. Patterns of Division of the Middle Cerebral Artery within the Sylvian Fissure.- 2. Frontal Branches of the Middle Cerebral Artery.- 3. Parietal Branches of the Middle Cerebral Artery.- 4. Temporal and Temporo-Occipital Branches of the Middle Cerebral Artery.- 5. Insular Branches.- II. Radiologic Study of the Middle Cerebral Artery.- C. Anterior Choroidal Artery.- I. Anatomic Study of the Anterior Choroidal Artery.- II. Radiologic Study of the Anterior Choroidal Artery.- D. Posterior Cerebral Artery.- I. Anatomic Study of the Posterior Cerebral Artery.- II. Radiologic Study of the Posterior Cerebral Artery.- 4. Basal Cerebral Vein (Y. P. H.).- A. Normal Anatomy.- I. First Segment of the Basal Cerebral Vein and Its Tributaries.- 1. Deep Middle Cerebral Vein.- 2. Inferior Striate Veins.- 3. Olfactory Vein.- 4. Fronto-Orbital Veins.- 5. Anterior Cerebral and Pericallosal Veins.- 6. Veinlets from the Optic Chiasm, Optic Tract, and Adjacent Structures.- II. Second Segment of the Basal Cerebral Vein and Its Tributaries>.- 1. Peduncular Vein.- 2. Inferior Ventricular Vein.- III. Third Segment of the Basal Cerebral Vein and Its Tributaries.- 1. Lateral Mesencephalic Vein.- 2. Lateral Atrial Vein.- 3. Medial Temporal and Occipitotemporal Cortical Veins.- 4. Posterior Longitudinal Hippocampal Vein.- 5. Posterior Thalamic Veins.- B. Anatomic Variations.- 2. Mesencephalic Region, Diencephalic Region, and Basal Ganglia.- 1. Third Ventricle and Suprasellar Cisterns (G. S.).- I. Anatomic Study of the Third Ventricle and Suprasellar Cisterns.- 1. Third Ventricle.- 2. Suprasellar Cisterns.- II. Radiologic Study of the Third Ventricle and Suprasellar Cisterns.- 2. Aqueduct of Sylvius (G. S.).- I. Anatomic Study of the Aqueduct of Sylvius.- II. Radiologic Study of the Aqueduct of Sylvius.- 3. Arteries of the Basal Ganglia and the Posterior Choroidal Arteries (G. S.).- I. Anatomic Study of the Perforating Arteries of the Basal Ganglia and of the Posterior Choroidal Arteries.- 1. Perforating Branches of the Carotid System.- a) Perforating Branches of the Anterior Cerebral Artery.- b) Perforating Branches of the Middle Cerebral Artery.- c) Perforating Branches of the Anterior Choroidal Artery.- 2. Perforating Branches of the Vertebrobasilar System.- a) Arteries to the Inferior Surface of the Thalamus.- b) Arteries to the Posterior Surface of the Thalamus.- c) Arteries to the Superior Surface of the Thalamus.- II. Radiologic Study of the Perforating Arteries of the Basal Ganglia and of the Posterior Choroidal Arteries.- 4. Deep Cerebral Veins (Y. P. H.).- A. Internal Cerebral and Great Cerebral Veins.- B. Subependymal Veins of the Lateral Ventricle.- I. Medial Group of theSubependymal Veins.- 1. Septal Vein.- 2. Posterior Septal Vein.- 3. Medial Atrial Vein.- 4. Transverse Hippocampal Subependymal Veins.- II. Lateral Group of the Subependymal Veins.- 1. Thalamostriate Vein.- 2. Direct Lateral Vein.- 3. Inferior Ventricular Vein.- C. Choroidal Veins of the Lateral Ventricle.- D. Veins of the White Matter of the Cerebral Hemisphere-Medullary Veins.- E. Veins of the Grey Matter of the Cerebral Hemisphere.- 3. Posterior Fossa.- 1. Fourth Ventricle and Cisterns of the Posterior Fossa (G. S.).- I. Anatomic Study of the Fourth Ventricle.- 1. Floor of the Fourth Ventricle.- 2. Roof of the Fourth Ventricle t2.- II. Anatomic Study of the Posterior Fossa Cisterns.- 1. Cisterns Anterior to the Brainstem.- a) Medullary Cistern.- b) Pontine Cistern.- c) Cerebellopontine Angle Cistern.- 2. Cistern Posterior to the Medulla and Below the Inferior Vermis-Cisterna Magna.- 3. Cisterns Posterior to the Tectum and Superior to the Cerebellum.- 4. Cisterns Around the Cerebral Peduncles.- III. Radiologic Study of Posterior Fossa, Fourth Ventricle and Cisterns of the Posterior Fossa.- 2. Arteries of the Vertebrobasilar System (G. S.).- I. Anatomic Study of the Arteries of the Vertebrobasilar System.- 1. Intracranial Segment of the Vertebral Artery.- 2. Basilar Trunk.- 3. Arteries of the Brainstem.- a) Arteries of the Medulla.- b) Arteries of the Pons.- c) Arteries of the Cerebral Peduncles.- 4. Arteries of the Cerebellum.- a) Superior Cerebellar Artery-SCA.- b) Anterior Inferior Cerebellar Artery-AICA.- c) Posterior Inferior Cerebellar Artery-PICA.- II. Radiologic Study of the Arteries of the Vertebrobasilar System.- 1. Basilar Trunk and Its Branches.- 2. Anterior. Inferior Cerebellar Artery-AICA.- 3. Superior Cerebellar Artery-SCA.- 3. Veins of the Posterior Fossa (Y. P. H.).- I. Superior or Galenic Draining Group.- 1. Mesencephalic Tributaries.- 2. Cerebellar Tributaries.- II. Anterior or Petrosal Draining Group.- 1. Tributaries Related to the Anterior Aspect of the Brain Stem.- 2. Tributaries Related to the Wing of the Precentral Cerebellar Fissure.- 3. Tributaries Related to the Posterolateral Fissure.- 4. Tributaries Related to the Cerebellomedullary Fissure.- 5. Tributaries Related to the Cerebellar Hemisphere.- III. Posterior or Tentorial Draining Group.- IV. Intercommunications Among the Superior, Anterior and Posterior Draining Groups and Between the Supra- and Infratentorial Veins.- V. Circulation Times of Veins of the Posterior Fossa.- References.

Knowledge of the radiologic anatomy of the posterior fossa has certainly benefited from recent investigations into the arterial supply and venous drainage of its structures, and from studies of the anatomy of the fourth ventricle and cisterns of the posterior fossa.

The vascularization of the lentiform nucleus, the caudate nucleus, the thalamus and the internal capsule is provided by perforating arteries which arise from the anterior, middle and posterior cerebral arteries and the anterior choroidal arteries. The carotid branches supply the nuclei of telencephalic origin (caudate and lentiform) while the vertebrobasilar branches supply the diecephalic nuclei (thalamus).