Response to Comment on "Cryoforged nanotwinned titanium with ultrahigh strength and ductility"

We address the three main points of Guo et al. They claim that we should have used the engineering stress versus engineering strain curves to infer the mechanical properties of our nanotwinned titanium, question our sample design on the basis of a finite-element analysis, and doubt the immobility of some preexisting grain/twin boundaries in our electron backscatter diffraction micrographs. We find their analysis to be groundless and to contain many inconsistencies.

Cryoforged nanotwinned titanium with ultrahigh strength and ductility

[Figure: see text].

Making ultrastrong steel tough by grain-boundary delamination

Developing ultrahigh-strength steels that are ductile, fracture resistant, and cost effective would be attractive for a variety of structural applications. We show that improved fracture resistance in a steel with an ultrahigh yield strength of nearly 2 gigapascals can be achieved by activating delamination toughening coupled with transformation-induced plasticity. Delamination toughening associated with intensive but controlled cracking at manganese-enriched prior-austenite grain boundaries normal to the primary fracture surface dramatically improves the overall fracture resistance. As a result, fracture under plane-strain conditions is automatically transformed into a series of fracture processes in "parallel" plane-stress conditions through the thickness. The present "high-strength induced multidelamination" strategy offers a different pathway to develop engineering materials with ultrahigh strength and superior toughness at economical materials cost.

A Nanobionic Light-Emitting Plant

The engineering of living plants for visible light emission and sustainable illumination is compelling because plants possess independent energy generation and storage mechanisms and autonomous self-repair. Herein, we demonstrate a plant nanobionic approach that enables exceptional luminosity and lifetime utilizing four chemically interacting nanoparticles, including firefly luciferase conjugated silica (SNP-Luc), d-luciferin releasing poly(lactic-co-glycolic acid) (PLGA-LH₂), coenzyme A functionalized chitosan (CS-CoA) and semiconductor nanocrystal phosphors for longer wavelength modulation. An in vitro kinetic model incorporating the release rates of the nanoparticles is developed to maximize the chemiluminescent lifetimes to exceed 21.5 h. In watercress (Nasturtium officinale) and other species, the nanoparticles circumvent limitations such as luciferin toxicity above 400 μM and colocalization of enzymatic reactions near high adenosine triphosphate (ATP) production. Pressurized bath infusion of nanoparticles (PBIN) is introduced to deliver a mixture of nanoparticles to the entire living plant, well described using a nanofluidic mathematical model. We rationally design nanoparticle size and charge to control localization within distinct tissues compartments with 10 nm nanoparticles localizing within the leaf mesophyll and stomata guard cells, and those larger than 100 nm segregated in the leaf mesophyll. The results are mature watercress plants that emit greater than 1.44 × 10¹² photons/sec or 50% of 1 μW commercial luminescent diodes and modulate "off" and "on" states by chemical addition of dehydroluciferin and coenzyme A, respectively. We show that CdSe nanocrystals can shift the chemiluminescent emission to 760 nm enabling near-infrared (nIR) signaling. These results advance the viability of nanobionic plants as self-powered photonics, direct and indirect light sources.

Optimization of in vitro cultivation strategies for human adipocyte derived stem cells

With adipose-derived stem cells being in the focus of research in regenerative medicine, the need arises for fast reliable cultivation protocols. We have tested the cultivation of human adipose-derived stem cells in endothelial cell growth medium prior to induction and differentiation, against the long-established use of DMEM/F12 medium-based cultivation protocols. We found that cultivation in endothelial cell growth medium not only accelerates growth before induction and differentiation, but also allows shorter induction and differentiation times than those following precultivation with DMEM/F12 medium with regard to the formation of mature adipocytes and to the viability undifferentiated cells. These results were first observed morphologically but could be confirmed by performing adiponectin ELISA and cell proliferation assays.

Basilar impression complicating osteogenesis imperfecta type IV: the clinical and neuroradiological findings in four cases

OBJECTIVES

To describe the clinical and neuroradiological features of basilar impression in patients with osteogenesis imperfecta type IV.

METHODS

Four patients with basilar impression were ascertained in a population study of osteogenesis imperfecta. All four had detailed clinical and neuroradiological examination with both CT and MRI of the craniocervical junction and posterior fossa structures.

RESULTS

All four showed significant compression of the posterior fossa structures and surgical decompression was performed with relief of symptoms.

CONCLUSION

Symptoms of cough headache and trigeminal neuralgia occurring in patients with osteogenesis imperfecta are indications for detailed clinical and neuroradiological investigation to document basilar impression.

The Wolf-Hirschhorn syndrome in adulthood: evaluation of a 24-year-old man with a rec(4) chromosome

We described a profoundly intellectually disabled 24-year-old man with Wolf-Hirschhorn syndrome, left hemiplegia, epilepsy, atrophy of the right cerebral hemisphere, and dilatation of the right ventricle. The patient had a small ventricular septal defect, was wheelchair bound, and totally dependent. He had no speech, but vocalised to show his feelings. In this patient, the del(4)(p15) was subtle and arose due to the inheritance of a recombinant chromosome (4) from a maternal pericentric inversion-46,XX,inv(4) (p15.32q35). Fluorescence in situ hybridisation with probe D4S96 confirmed the deletion. This is the second case of Wolf-Hirschhorn syndrome resulting from a large pericentric inversion of chromosome 4.

MR and positron emission tomography with fludeoxyglucose F 18 in gliomatosis cerebri

A 16-year-old girl presented with a unilateral third nerve palsy and predominant gray matter involvement on MR and positron emission tomography with fludeoxyglucose F 18. These findings were manifestations of gliomatosis cerebri. The antemortem diagnosis was made by partial temporal lobectomy.

Dizziness--organic or functional?

The author discusses a specific case to illustrate the problem of chronic, uncompensated asymmetrical vestibular function, which can present with seemingly bizarre symptoms. Simple guidelines to distinguish between organic and functional dizziness are offered.

Lymphomatoid granulomatosis presenting as sudden blindness

Lymphomatoid granulomatosis is an uncommon clinical problem and even more rarely presents to the ophthalmologist. A case is described in which a 60-year-old Fijian woman presented with sudden, sequential, complete visual loss in association with signs of scleritis. Direct eyewall biopsy and nasal mucosal biopsy confirmed the diagnosis of lymphomatoid granulomatosis. Despite intensive high-dose oral prednisone therapy her vision remained at no light perception and she developed recrudescence of disease necessitating the use of radiotherapy. All systemic investigations failed to show any other organ involvement by the disease process and she remains well. This is the first report of lymphomatoid granulomatosis presenting as sudden blindness.

Neuro-otological abnormalities in Friedreich's ataxia

Ten patients with an accepted diagnosis of Friedreich's ataxia have been examined neuro-otologically, and oculomotor, vestibular and auditory function assessed. Brainstem auditory evoked potentials (BAEPs) were also recorded. A high incidence of various eye movement disorders was noted. Some of these were indicative of cerebellar dysfunction. Reduced vestibular function and impaired hearing were common to most of the patients. BAEPs were also abnormal in the majority; reasons underlying these abnormalities are discussed. Neuro-otologically, the patients did not constitute an homogeneous group. The findings cast doubt upon the accuracy and validity of the currently accepted criteria for the diagnosis and classification of the spinocerebellar degenerations.

The effects of the "vestibular sedative" drug, Flunarizine upon the vestibular and oculomotor systems

The effects of the "vestibular sedative" drug Flunarizine upon the oculomotor functions of pursuit and voluntary saccades and upon the vestibular response (to rotational stimuli) were assessed in twenty volunteer subjects. The study was then extended to three patients with chronic imbalance of central origin who had reported a beneficial symptomatic response to the drug. Three of the volunteer subjects were found to have a directional preponderance (presumed to arise from peripheral dysfunction). In the remaining seventeen normal subjects Flunarizine was found to reduce the amplitudes of fast phases of vestibular nystagmus. The directional preponderance in the other three subjects was redressed through production of fast phases which were of lower and more uniform amplitude. In the patients, in addition to a reduction in fast phase amplitude, there was a reduction or abolition of after nystagmus. In no case was any reduction in slow phase velocity observed. Pursuit and voluntary saccades were unaffected by the drug. It was concluded, on the basis that the fast phases of nystagmus are centrally generated, that Flunarizine has a central action rather than a depressant effect upon the vestibular end organ. In view of known oculomotor physiology and pharmacology it is proposed that vestibular sedatives act by depression of Type II vestibular neurons, and modification of the functional relationships between the vestibular nuclei, the perihypoglossal nuclei and the flocculus of the cerebellum. A trial of vestibular active drug is indicated particularly in patients in whom asymmetry of the vestibular response and/or abnormal after nystagmus is demonstrated.