[Thoughts and suggestions on digital services to enhance the level of vaccination management]

With the development of information technology and the increasing demand for vaccination services among the people, it is a definite trend to enhance the quality of vaccination services through digitization. This article starts with a clear concept of digital services for vaccination, introduces the current development status in China and abroad, analyzes the advantages and disadvantages of existing models in leading regions, takes a glean from the summation, and proposes targeted solutions. This study suggests establishing a departmental coordination mechanism for data interconnection and sharing, formulating data standards and functional specifications, enhancing the functionalities of the immunization planning information system, strengthening data collection and analytical usage, and intensifying appointment management and science and health education to provide expert guidance for the construction of digital vaccination services across the country in the future.

[Clinical analysis of laparoscopic treatment of chronic traumatic diaphragmatic hernia in 29 cases]

Objective: To examine the safety and effectiveness of laparoscopic individualized surgical treatment for chronic traumatic diaphragmatic hernia (CTDH). Methods: The clinical data and follow-up data of 29 CTDH cases admitted to the Qilu Hospital of Shandong University or the First Affiliated Hospital of Shandong First Medical University from June 2015 to January 2023 were retrospectively analyzed. There were 21 males and 8 females, aged (49.4±17.8) years (range: 19 to 79 years). The main clinical manifestations were symptoms of the digestive system and respiratory system, and only 4 cases were asymptomatic. All patients received laparoscopic treatment (conversion to open surgery was not excluded). Intraoperative exploration (location of the hernia, contents of the hernia, diameter of the hernia ring), surgical conditions (surgical repair plan, operation time, blood loss, postoperative complications) and postoperative follow-up were analyzed and discussed. Results: Laparoscopic repair was successfully completed in 27 cases, including simple suture in 6 cases, suture and patch repair in 17 cases, the anterior abdominal wall muscle flap reversal suture and patch repair of in 3 cases, and patch bridge repair in 1 case. The operation time was (112.8±44.7) minutes (range: 60 to 200 minutes). The amount of bleeding (M(IQR)) was 35 (58) ml (range: 10 to 300 ml). The other 2 patients were converted to laparotomy. Except for one patient with transverse colon strangulation necrosis who died of aggravated pulmonary infection after surgery, the remaining 28 patients were discharged successfully. The follow-up time was 36 (24) months (range: 1 to 60 months). During the follow-up period, only two patients had occasional left upper abdominal discomfort. Twenty-seven patients with left diaphragmatic hernia had no recurrence, and the symptoms of 1 patient with right diaphragmatic hernia were relieved. Conclusion: Customized laparoscopic surgical repair for CTDH according to the location and size of the diaphragmatic defect can achieve good surgical results.

[Analysis on the scrap situation of COVID-19 vaccine in Suzhou city]

To analyze the usage and loss of the COVID-19 vaccine in ten districts of Suzhou city from December 18, 2020 to April 30, 2021.The results showed the loss rate was 0.222‰ in Suzhou city. The loss rate of pre-filled packaging COVID-19 vaccine was higher than that of vial packaging. The loss rate of 40 packaging was the lowest in vial packaging. The loss rate of all kinds of COVID-19 vaccine in stable inoculation unit was the lowest. It is recommended to distribute 40 vial packaging COVID-19 vaccine for centralized vaccination to reduce the loss of COVID-19 vaccine.

Direct Synthesis of Sulfur-Decorating PAMAM Dendrimer/Mesoporous Silica for Enhanced Hg(II) and Cd(II) Adsorption

Water security caused by heavy metals poses a deleterious hazard to public health and the ecological system. The construction of adsorbents by polyamidoamine (PAMAM) dendrimers for efficient removal of metal ions has attracted considerable interest. However, the general method for the fabrication of these adsorbents was achieved by the surface chemical modification of the substrates with PAMAM dendrimer, which usually causes the defects of low density and uneven distribution of the dendrimer, the blocking of pores, and reducing the adsorption performance. Hence, the development of a new method for preparation of PAMAM dendrimer-based adsorbent to realize the efficient and enhanced adsorption of metal ions is still a challenge. Herein, methylisothiocyanate decorated PAMAM dendrimer/mesoporous silica composites (G0-S-1/x, G1.0-S-1/x, G2.0-S-1/x, x = 2, 4, 6, 8, 10) were synthesized by the direct sol-gel reaction of alkoxysilyl-containing functional PAMAM dendrimer. The adsorbents display enhanced adsorption property for Hg(II) and Cd(II) as compared with the same adsorbents which were prepared by traditional chemical modification method. Take G2.0-S-1/2 as an example, the maximum adsorption capacities are 2.41 and 0.87 mmol·g^-1 for Hg(II) and Cd(II), respectively . Moreover, the adsorbents show excellent selective adsorption and regeneration property. G2.0-S-1/2 displays distinct selectivity for Hg(II) with the presence of Co(II), Pb(II), Cd(II), and Cu(II). The regeneration percentage still maintains 95.2% after five adsorption-desorption cycles. The adsorption mechanism is also certified by the experimental method and theoretical calculation.

Screening for active and latent TB among migrants in France

SETTING: Migrants to Europe face a disproportionate burden of infections, including TB, yet little is known about the approach taken by primary and secondary care providers to screening and treatment. We therefore explored policy and practice relating to screening of active TB and latent TB infection (LTBI) in France.METHODS: We conducted an online national survey of French primary and secondary care physicians regarding their practices in relation to TB/LTBI screening among migrants.RESULTS: 367 physicians responded to the questionnaire among which 195 (53.1%) were primary care physicians, 126 (34.3%) were TB specialists in secondary care, and 46 (12.5%) other physicians; 303 (85.5%) were involved daily in the care of migrants. Most respondents recommended systematic TB screening with chest X-ray for migrants from medium and high-incidence countries (71.9%). Primary care physicians were less likely to offer screening than physicians in other settings (aOR 0.21, 95% CI 0.09-0.48). 220 (61.8%) offered LTBI screening for children (<15 years) and 34.0% for all migrants from high incidence countries.CONCLUSION: Improving awareness on TB screening is a critical next step to improve health outcomes in migrant groups and meet regional targets for tackling TB.

Screening for tuberculosis among newly arrived migrants in France. Results from a practice study

Background

Screening of active and latent tuberculosis among migrants is a public health concern but physicians’ practices are poorly known. The study aimed to evaluate physicians’ practices in France.

Methods

A national survey of physicians’ practices about infectious diseases prevention among migrants was conducted in 2017-2018 and broadcasted by several scientific societies.

Results

In total, 367 physicians answered; 53.1% were primary care physicians, 34.3% “TB involved physicians”, and 85.5% were involved daily with migrants. Screening by chest X ray is recommended by 84.8%, 71.9% and 38.4% of participants for migrants from high- (&gt;100 cases/100,000 p.a.), medium- (&gt; 50/100,000), and low-incidence countries respectively. One physician in two declares considering migration conditions in his/her decision of screening migrants from low incidence countries. Primary care physicians are less likely to offer screening (aOR= 0.21[0.09-0.48], p &lt; 0.001). About screening prescription, only 55.6% consider it their responsibility. TB control centres are designated by 56.7% of respondents. Concerning screening for latent tuberculosis infection (LTBI), 61.8% and 34.0% offered screening for children under the age of 15 and for all migrants (adults and children) from high incidence countries respectively; physicians working in Paris and its region being less likely to offer it (aOR=0.45 [0.28-0.71], p = 0.001 and aOR=0.43 [0.27-0.69] p = 0.001 respectively). Among those screening children, 88.1% recommend treatment if facing a positive result, most often with a 3-month isoniazid rifampicin double therapy, and 11.4% offer follow up alone.

Conclusions

Physicians’ practices in France regarding screening of tuberculosis among migrants are heterogeneous. Which population should be targeted for LTBI screening remains unclear in the context of contradictory national and international recommendations. The results of our study raise the issue of knowledge, and adherence to these guidelines.

Key messages

Physicians’ practices in France concerning active and latent tuberculosis screening among newly arrived migrants are heterogeneous. Many physicians involved in migrants’ care ignore or do not adhere to current national guidelines, especially concerning LTBI screening among newly arrived migrants.

Differential toxicity of functionalized polystyrene microplastics to clams (Meretrix meretrix) at three key development stages of life history

Little knowledge is available on impact of microplastics (MPs) on the bivalve larvae at different developmental stages throughout their life history, especially for metamorphic stage. Therefore, this study aims to evaluate the toxic responses of carboxylated (PS-COOH) and amino (PS-NH₂) polystyrene MPs on the developing clam larvae at three key life stages, i.e., fertilized eggs, D-veliger larvae, and umbo larvae. PS-COOH and PS-NH₂ significantly decreased the hatching rates by 5.79-39.5% and developmental rates by 4.78-7.86% of the clam larvae relative to the unexposed clam larvae. The toxicity of MPs followed the order: hatching stage > metamorphosis > D-veliger larvae stage, showing stage-dependent toxic effects. Moreover, PS-NH₂ with a smaller hydrodynamic diameter showed a greater toxicity to the developing larvae compared to PS-COOH. Our study highlighted the stage-dependent toxic effects of MPs on the developing clam larvae, thus posing ecological risks to population succession of marine bivalves and aquatic ecosystems.

Hypoxia-inducible factor-1α regulation of myeloid cells

Hematopoietic myeloblasts give rise to macrophages, dendritic cells, and neutrophils. Circulating myeloid cells detect invading microbes using pattern recognition receptors and subsequently orchestrate an innate immune response to contain and kill the pathogens. This innate immune response establishes an inflammatory niche characterized by hypoxia due to host and pathogen factors. Hypoxia-inducible factor (HIF) transcription factors are the primary regulators of the myeloid response to hypoxia. In particular, HIF-1α is a critical hub that integrates hypoxic and immunogenic signals during infection or inflammation. Hypoxia induces HIF-1α stabilization, which drives metabolic and phenotypic reprogramming of myeloid cells to maximize antimicrobial potential. HIF-1α activity in myeloid-derived cells enhances the host response to infection, but may also play a role in pathogenic inflammatory processes, such as atherosclerosis. In this review, we summarize recent advances that have elucidated the mechanism by which myeloid cells regulate HIF-1α activity and, in turn, how HIF-1α shapes myeloid cell function.

Histopathological and immunophenotypic features of ipilimumab-associated colitis compared to ulcerative colitis

BACKGROUND

Use of the immune checkpoint inhibitor ipilimumab is sometimes complicated by ipilimumab-associated colitis (Ipi-AC), an immune-mediated colitis that mimics inflammatory bowel disease.

OBJECTIVE

We sought to characterize the histopathologic and immunophenotypic features of Ipi-AC and to directly compare these features to ulcerative colitis (UC).

METHODS

This is a retrospective cohort study of 22 patients with Ipi-AC, 12 patients with treatment-naïve UC and five controls with diarrhoea but normal endoscopic findings. Immunohistopathologic features were described, and quantitative immunohistochemistry (IHC) was performed for CD4, CD8, CD20, CD138 and FOXP3.

RESULTS

Endoscopic findings in both the Ipi-AC and UC groups included ulcerated, oedematous and erythematous mucosa. Involvement of the GI tract was more diffuse in Ipi-AC. As compared to UC, a smaller proportion of Ipi-AC biopsies had basal plasmacytosis (14% for Ipi-AC vs. 92% for UC, P < 0.0001) and crypt distortion (23% for Ipi-AC vs. 75% for UC, P = 0.003), whereas Ipi-AC biopsies had more apoptotic bodies in the left colon (17.6 ± 15.3 for Ipi-AC vs. 8.2 ± 4.2 for UC, P = 0.011). Cryptitis, ulcerations and crypt abscesses were common in both groups. Biopsy specimens from Ipi-AC had a lower density of CD20-positive lymphocytes than UC (275.8 ± 253.3 cells mm^-2 for Ipi-AC vs. 1173.3 ± 1158.2 cells mm^-2 for UC, P = 0.022) but had a similar density of CD4, CD8, CD138 and FOXP3-positive cells.

CONCLUSIONS

Ipi-AC is a distinct pathologic entity with notable clinical and histopathological differences compared to UC. These findings provide insights into the pathophysiology of immune-related adverse events (iAEs) from ipilimumab therapy.

Stroke increases the risk of hip fracture: a systematic review and meta-analysis

Many studies have investigated the association between stroke and hip fracture risk, but the precise association was still unclear due to insufficient statistical power in single studies with relatively small sample size. Thus, we firstly conducted a meta-analysis of all published studies to precisely estimate the relationship of stroke with hip fracture risk. The strength for this relationship was weighed by pooled relative risks (RRs) with 95 % confidence intervals (95 % CIs) after adjustment for confounding variables. Stratified analyses by study design and ethnicity and sensitivity analysis were also performed. Two investigators independently performed a comprehensive literature search in databases of PubMed, Embase, and Wanfang for eligible articles. A Bayesian meta-analysis was also performed to get a more precise assessment of the relationship. Eleven relevant studies from 10 publications were finally included into our meta-analysis according to the inclusion criteria. Overall, stroke significantly and independently increased the risk of hip fracture (RR = 2.06, 95 % CI 1.68-2.52, P < 0.001). Bayesian meta-analysis showed that stroke was also associated with an over two-fold increased risk of hip fracture (RR = 2.11, 95 % CI 1.62-2.75). In stratified analysis, stroke could increase the risk of hip fracture in Caucasians (RR = 2.36, 95 % CI 1.83-3.05, P < 0.001). These data support the notion that stroke is an independent risk factor for hip fracture, and patients with stroke have a two-fold increased risk of hip fracture than those without stroke.

Simultaneous determination of aflatoxin B1, aflatoxin B2, mycophenolic acid and sterigmatocystin in grape pomace by UHPLC-MS/MS

A reliable ultrahigh performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed for the simultaneous determination of aflatoxin B1, aflatoxin B2, mycophenolic acid and sterigmatocystin in grape pomace. The samples were extracted by acetonitrile aqueous solution and further purified using a solid-phase extraction-based homemade clean-up cartridge. Next, the analytes were separated on a reversed-phase C18 column with a mobile phase consisting of water and acetonitrile. The separated compounds were detected with a tandem quadrupole mass spectrometer operating in positive electro-spray ionisation mode using multiple reaction monitoring. The established method was extensively validated by determining linearity (R2≯0.999), recovery (97.5-102.8%) and precision (relative standard deviation ≤7.0%). This method was then used for the simultaneous determination of the four mycotoxins in grape pomace samples.

A comparative cytogenetic study of the rice (Oryza sativa L.) autotetraploid restorers and hybrids

We studied pollen fertility, seed set and cytogenetic characteristics of restorer lines and F1 hybrids of autotetraploid rice. T4002, T4063, T461A x T4002 and T461A x T4063 showed significantly higher pollen fertility and seed set than T4132 and T461A x T4132. Meiotic pairing configurations of T4002, T4063, T4132, T461A x T4002, T461A x T4063 and T461A x T4132 were 0.051 + 19.96II (9.89 rod + 10.07 ring) + 0.01III + + 2.00IV, 0.11I + 19.17II (8.90 rod + 10.37 ring) + 0.09III + 2.26IV + 0.01VI, 1.34I + 9.46II (4.50 rod + 4.96 ring) + 0.80III + 6.02IV + 0.09VI + 0.09VIII, 0.02I + 14.36II (6.44 rod + 7.91 ring) + 0.01III + 4.80IV + 0.01VIII, 0.06I + 17.67II (11.01 rod + 6.67 ring) + 0.06III + 3.10IV + 0.01VI and 1.11I + 11.31II (5.80 rod + 5.51 ring) + 0.41III + 5.63IV + 0.03VI + 0.03VIII, respectively. Configuration 16II + 4IV and 12II + 6IV occurred in the highest frequency among the autotetraploid restorers and hybrids. Meiotic chromosome behaviors were less abnormal in the tetraploids with high seed set than those with low seed set. The hybrids had fewer frequencies of bivalents, univalents, trivalents and multivalents than the restorers, but higher frequency of quatrivalents than the restorers at MI. The frequency of univalents at MI had the most impact on pollen fertility and seed set, i.e., pollen fertility decreased with the increase of univalents. The secondary impact factors were trivalents and multivalents, and bivalents and quatrivalents had no effect on pollen fertility and seed set. The correlative relationship between pollen fertility and cytogenetic behaviors could be utilized to improve seed set in autotetraploidy breeding.

Alginate-deriving oligosaccharide production by alginase from newly isolated Flavobacterium sp. LXA and its potential application in protection against pathogens

AIMS

To examine algino-oligosaccharide production by alginase from newly isolated Flavobacterium sp. LXA and its elicitor and antibacterial activity.

METHODS AND RESULTS

Algino-oligosaccharide production from alginate was carried out using alginase obtained from a newly isolated Flavobacterium sp. LXA. When alginase was partially purified by dual ammonium sulfate precipitation and used for alginate degradation, the viscosity loss correlated well with the release of reducing terminals. The optimal temperature and pH for alginate degradation was 40 degrees C and pH 7.0, respectively. When alginate was added at an initial concentration of more than 0.8%, the maximal degradation rate of alginate was obtained. Under these optimal reaction conditions and with partially purified alginase, the average degrees of polymerization (DP) of alginate-degraded products was about 6.0, which favoured algino-oligosaccharide production. The algino-oligosaccharides showed an elicitor activity stimulating the accumulation of phytoalexin and inducing phenylalanine ammonia lyase in soybean cotyledon, and antimicrobial activity on Pseudomonas aeruginosa.

CONCLUSIONS

Algino-oligosaccharide could be degraded from alginate by the partially purified alginase and its maximal bioactivity occurred on the oligosaccharide with average DP 6.8.

SIGNIFICANCE AND IMPACT OF THE STUDY

Algino-oligosaccharide was first reported to have elicitor and antibacterial activity and have potential as a biological agent for protection against plant or human disease.

MRI-based investigation on outflow segment of cerebral venous system under increased ICP condition

OBJECTIVE

Increased intracranial pressure (ICP) is responsible for causing most nervous system diseases to progress seriously, till death. Recently, volume-targeted therapeutic strategy against increased ICP, which works by releasing excessive intracranial liquid especially from the venous compartment, attracted a great deal of attention. Previous research by us found a structurally special "outflow segment cuff" that is located at the juncture of superior sagittal sinus (SSS) and the brain-bridging veins in porcine model. Sequential observation demonstrated that this special structure appeared to have functional abnormalities. Based on these findings, it was proposed to try and prove a further hypothesis that there exists a similar structure in human beings that might be of importance for cerebral venous system to intervene in volume-initiated ICP regulation. Meanwhile, the diameters of bridging veins under either increased or normal ICP are compared by means of magnetic resonance imaging (MRI).

METHOD

Forty patients who presented with increased ICP were selected to undergo 2D time of flight (TOF) venography and ten normal volunteers were taken as the control group. Increased intracranial pressure status was evaluated by using flash visual evoked potential (fVEP) technique. All the patients and volunteers underwent 2D-TOF MRI imaging for the following parameters: repetition time/echo time, 50/4.9 milliseconds; flip angle, 45 degrees ; field of view, 250x250 mm; matrix, 256x256 pixels; section thickness, 1.5 mm. Syngo fastview imaging system was used to process and analyze the targeted brain-bridging venous section.

RESULTS

By using 2D-TOF method in vivo, most bridging venous profiles as well as SSS and vicinal cortical veins could be clearly visualized. A short and narrow section, as previously described, obviously emerged because of MRI signal weakness even disappearing at the juncture of SSS and bridging veins in increased ICP patients. In combination with previous animal morphological findings we believe that this section with abnormal MRI signal could stand for the human counterpart of "outflow segment cuff" in porcine. Such a special structure could be observed within a majority of increased ICP patients (32/40 cases), whereas only one case presented the existence of similar imaging signal weakness. Furthermore, the diameters of the bridging veins in increased ICP group are statistically larger than the control group.

CONCLUSION

Intracranial venous compartment occupies about 70 to 80% blood volume inside the inflexible cranial cavity. Following volume-targeted rationale, ICP can be regulated effectively by the fluctuation of venous blood volume based on different aspects of morphology, biomechanics, and hemodynamics. In the present study, the coincidence of animal model and human venography in vivo offers strong evidences to support the hypothesis that venous hemodynamics, although passively, influences intracranial pressure environment through a possible key regulator - outflow segment narrow structure. The fact that this narrow formation and proximal vascular dilation appears more in patients under high ICP condition rather than in patients with normal pressure. Both narrow formation and proximal vascular dilation indicate its significant contribution to intracranial venous congestion, resulting from difficult drainage and the close relationship between intracranial venous volume and ICP.

Moment switching in nanotube magnetic force probes

Magnetic images of high density vertically recorded media using metal-coated carbon nanotube tips exhibit a doubling of the spatial frequency under some conditions (Deng et al 2004 Appl. Phys. Lett. 85 6263). Here we demonstrate that this spatial frequency doubling is due to the switching of the moment direction of the nanotube tip. This results in a signal which is proportional to the absolute value of the signal normally observed in MFM. Our modeling indicates that a significant fraction of the tip volume is involved in the observed switching, and that it should be possible to image high bit densities with nanotube magnetic force sensors.

Osteoblast proliferation on hydroxyapatite thin coatings produced by right angle magnetron sputtering

Right angle magnetron sputtering (RAMS) was used to produce hydroxyapatite (HA) film coatings on pure titanium substrates and oriented silicon wafer (Si(0 0 1)) substrates with flat surfaces as well as engineered surfaces having different forms. Analyses using synchrotron XRD, AFM, XPS, FTIR and SEM with EDS showed that as-sputtered thin coatings consist of highly crystalline hydroxyapatite. The HA coatings induced calcium phosphate precipitation when immersed in simulated body fluid, suggesting in vivo bioactive behavior. In vitro experiments, using murine osteoblasts, showed that cells rapidly adhere, spread and proliferate over the thin coating surface, while simultaneously generating strong in-plane stresses, as observed on SEM images. Human osteoblasts were seeded at a density of 2500 cells cm(-2) on silicon and titanium HA coated substrates by RAMS. Uncoated glass was used as a reference substrate for further counting of cells. The highest proliferation of human osteoblasts was achieved on HA RAMS-coated titanium substrates. These experiments demonstrate that RAMS is a promising coating technique for biomedical applications.

[Identification of corrected retention indices of ten phenols in reversed-phase high performance liquid chromatography]

Corrected retention indices in RP-HPLC of ten phenols based on 2-keto-alkanes were examined on three ODS-silica columns. The RI values for phenols showed large variations. However, when the correction was applied, the variations diminished significantly. It is clear that the correction procedure improves the variation of phenols' RI values obtained from different ODS columns. The procedure is recommended as a method of standardization of HPLC data.

[Prediction of RP-HPLC retention index for hydroxyl-containing compounds and their glucuronides]

The quantitative relationships between the structure of solutes and their chromatographic retention behaviors have been widely studied. A lot of compounds have been investigated, but drug metabolites have not been involved. Determination of glucuronic acid conjugation is the most important route for investigations of metabolism of drug, while the glucuronide samples are rarely obtained. In this paper the glucuronides have been obtained with the method of biosynthesis in vitro. The peaks of glucuronides were identified by several means including diode-array spectrophotometer detection, beta-D-glucuronidase hydrolysis, glucuronide references and chromatogram comparison of the incubation samples at different times. Two systems have been developed to predict retention index in reversed-phase high performance liquid chromatography based on the molecular structure of the analytes and on the behavior of the parent compounds. We observed a good correlation between retention index of hydroxyl-containing compounds of glucuronides and hydrophobility based on Hansh pi value: I=383.4+136.0pi, n=10, r=0.9912. A good correlation between hydroxyl-containing compounds and their glucuronides was also observed: Y=-471.1+1.4430X, n=11, r=0.9600. The errors in this experiment are less than 12%.

Purification and characterization of pranlukast hydrolase from rat liver microsomes: the hydrolase is identical to carboxylesterase pI 6.2

Two carboxylesterases with pI 6.0 and 6.2 derived from rat liver microsomes were purified. The two isozymes were remarkably different in substrate specificity, but they had equal enzymatic activity for alpha-naphthyl acetate and were inhibited equally by phenylmethylsulfonyl fluoride (PMSF) and bis-(4-nitrophenyl) phosphate (BNPP). Carboxylesterases pI 6.0 and 6.2 are identical to the enzymes referred to as hydrolase A and B, respectively, from the results of amino acid sequence analyses. Pranlukast was effectively hydrolyzed by carboxylesterase pI 6.2 but not by the pI 6.0 enzyme, and the difference in the pranlukast metabolism between the human and the rat could be explained by the substrate specificity of carboxylesterase. Furthermore, prodrugs of angiotensin converting enzyme inhibitors were found to be converted to the active drugs after hydrolysis by the carboxylesterases pI 6.0 and 6.2. Carboxylesterases generally catalyze the hydrolysis of ester-type drugs preferentially rather than amide-type drugs.