Reversible switching between superhydrophobic states on a hierarchically structured surface

Nature offers exciting examples for functional wetting properties based on superhydrophobicity, such as the self-cleaning surfaces on plant leaves and trapped air on immersed insect surfaces allowing underwater breathing. They inspire biomimetic approaches in science and technology. Superhydrophobicity relies on the Cassie wetting state where air is trapped within the surface topography. Pressure can trigger an irreversible transition from the Cassie state to the Wenzel state with no trapped air--this transition is usually detrimental for nonwetting functionality and is to be avoided. Here we present a new type of reversible, localized and instantaneous transition between two Cassie wetting states, enabled by two-level (dual-scale) topography of a superhydrophobic surface, that allows writing, erasing, rewriting and storing of optically displayed information in plastrons related to different length scales.     

Tibiotalocalcaneal arthrodesis with a compressive retrograde intramedullary nail: a report of 34 consecutive patients

BACKGROUND: Tibiotalocalcaneal arthrodesis is a treatment modality for severe arthrosis and malalignment of the hindfoot. Complications, such as delayed union and nonunion, are well-known risks of the procedure. Arthrodesis can be done with a plate, screws, an external fixator, or an intramedullary nail. Compression with an intramedullary nail was the focus of this report. METHODS: Thirty-four consecutive patients (23 men and 11 women) with an average age range of 57 (range 25-77) years had tibiotalocalcaneal arthrodesis using retrograde intramedullary compression nail fixation. Mean followup was 24 (range 6 to 43) months. One patient died of an unrelated cause, but 30 (91%) of the remaining 33 patients answered the questionnaire. RESULTS: Bony consolidation was achieved in 26 (76%) patients, the mean time to fusion being 16 weeks. Five patients (15%) had complications and seven (20%) had repeat surgery. Of the 30 patients who responded to the questionnaire, three patients (10%) evaluated the overall result subjectively as being of no benefit and 27 (90%) as improved. The visual analog scale (VAS) score for preoperative pain was 66 at rest and 83 when walking, and the mean postoperative scores were 19 and 32, respectively (p<0.001). CONCLUSIONS: Tibiotalocalcaneal arthrodesis with a compressive retrograde intramedullary nail is an effective and safe procedure for patients with severe malalignment or arthrosis of the hindfoot. It is essentially a salvage procedure, and most patients benefit from it, but excellent results are rare.     

Oscillatory motor cortex-muscle coupling during painful laser and nonpainful tactile stimulation

Noxious stimulation activates-in addition to the brain structures related to sensory, emotional, and cognitive components of pain-also the brain's motor system. Effect of noxious input on the primary motor (MI) cortex remains, however, poorly understood. To characterize this effect in more detail, we quantified the ongoing oscillatory communication between the MI cortex and hand muscles during selectively noxious laser stimulation. The subjects maintained an isometric contraction of finger muscles while receiving the laser stimuli to the dorsum of the hand. Tactile stimuli with well-known effects on the MI cortex reactivity served as control stimuli. Cortex-muscle coherence was computed between magnetoencephalographic (MEG) signals from the contralateral MI and electromyographic (EMG) signals from the hand muscles. Statistically significant coherence at approximately 20 Hz was found in 6 out of 7 subjects. The coherence increased phasically after both types of stimuli but significantly later after laser than tactile stimuli (mean +/- SEM peak latencies 1.05 +/- 0.12 s vs. 0.58 +/- 0.06 s; P < 0.05), and the coherence increase lasted longer after laser than tactile stimuli (0.87 +/- 0.09 s vs. 0.50 +/- 0.06 s, P < 0.05). The observed coherence increase could be related to stabilization of the motor-cortex control after sensory input. Our findings add to the clinically interesting evidence about the cortical pain-motor system interaction.     

How the harm reduction movement contrasts itself against punitive prohibition

On the basis of the harm reduction movement's founding texts from the beginning of the 1990s, this paper reflects the movement's self-understanding in contrasting itself with the system of punitive prohibition. Following this is a discussion of the implications for drug users of harm reduction claims-making. The paper concludes that the principles of the harm reduction movement resonate extremely well with the moral sensibilities of our contemporary societies, and but that the movement's claims for an amoral, rational, just, and emancipating approach to drug use are to be seen rather as a powerful rhetorical intervention in the highly moralised landscape of drug debate than something that would be achieved in practice.     

Rifampicin markedly decreases the exposure to oral and intravenous tramadol

Purpose

Tramadol is mainly metabolized by the cytochrome P450 (CYP) 2D6, CYP2B6 and CYP3A4 enzymes. The aim of this study was to evaluate the effect of enzyme induction with rifampicin on the pharmacokinetics and pharmacodynamics of oral and intravenous tramadol.

Methods

This was a randomized placebo-controlled crossover study design with 12 healthy subjects. After pretreatment for 5 days with rifampicin (600 mg once daily) or placebo, subjects were given tramadol either 50 mg intravenously or 100 mg orally. Plasma concentrations of tramadol and its active main metabolite O-desmethyltramadol (M1) were determined over 48 h. Analgesic and behavioral effects and whole blood 5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) concentrations were measured.

Results

Rifampicin reduced the mean area under the time–concentration curve (AUC_0-∞) of intravenously administered tramadol by 43 % and that of M1 by 58 % (P?<?0.001); it reduced the AUC_0-∞ of oral tramadol by 59 % and that of M1 by 54 % (P?<?0.001). Rifampicin increased the clearance of intravenous tramadol by 67 % (P?<?0.001). Bioavailability of oral tramadol was reduced by rifampicin from 66 to 49 % (P?=?0.002). The pharmacological effects of tramadol or whole blood serotonin concentrations were not influenced by pretreatment with rifampicin.

Conclusions

Rifampicin markedly decreased the exposure to tramadol and M1 after both oral and intravenous administration. Therefore, rifampicin and other potent enzyme inducers may have a clinically important interaction with tramadol regardless of the route of its administration.     

Drug user organizations in the Nordic countries--local, national, and international dimensions

The article focuses on drug user organizations that represent and advocate for active "hard drug" users in the Nordic countries. It discusses the opportunities and challenges that these organizations face in their search for legitimacy and political influence. The comparative perspective points at similarities and differences in national contexts that both support and challenges the existence of drug user organizations, including drug policy, social welfare policy, trends in drug use, and organizational conditions. The article also discusses the importance of international network and transnational organizations that support drug user organizations.     

Discovery Elbow System: clinical and radiological results after 2- to 10-year follow-up

Background

Discovery Elbow System (DES) is a semi-constrained prosthesis, mainly used for patients with rheumatoid arthritis (RA).

Methods

Records from 79 patients with RA (90 DES arthroplasties) were reviewed; 47 patients with 55 DES elbows were re-examined. Range of motion (ROM) of both elbows, upper limb function, and quality of life (Disabilities of the Arm, Shoulder, and Hand [DASH] score, Mayo Elbow Performance Score [MEPS], and the RAND 36-Item Health Survey [RAND-36]) were assessed. Cementing quality was assessed, and radiolucent lines measured from plain radiographs. Mean follow-up was 64 (range 24–123) months.

Results

Pre-operatively to post-operatively, mean elbow flexion improved from 120° to 146° (p < 0.001) and mean extension lag improved from 29° to 24° (p = 0.02), respectively. At follow-up, mean supination was 66°, mean pronation was 69°, and mean grip strength was 14 kg. Grip strength and ROM (except supination) were similar between the DES elbow and contralateral un-operated elbow. Mean post-operative MEPS was 93 points (excellent, n = 38; good, n = 14; fair, n = 2; and poor, n = 1). Mean DASH score was 43 points. The RAND-36 showed that physical functioning, physical role functioning, bodily pain, and general health were lower than the Finnish reference values. Primary cementing was challenging, and radiolucent lines appeared during follow-up. Four prostheses were revised because of aseptic loosening (n = 3) and periprosthetic fracture (n = 1).

Conclusion

DES provides significant improvement in patient’s flexion–extension arc. Cementing of the elbow prosthesis was challenging; radiolucent lines appeared during the 5-year follow-up, but their clinical relevance remains unclear. First-generation locking screws may loosen over time.

Level of evidence

Level IV.